noun · 13 senses · updated from the 2026-07-25 local source snapshot
Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.
Sound
Pronunciation
Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.
Received-Pronunciation:/ˈnjuː.kli.əs/
General-American:/ˈnuː.kli.əs/
US:Recorded audio is listed in the source snapshot.
CMU ARPABET:N UW1 K L IY0 AH0 S
Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.
1
noun
Meaning 1
The core, central part of something, around which other elements are assembled.
Definition source: English Wiktionary via Wiktextract
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
2
noun
Meaning 2
An initial part or version that will receive additions.
Definition source: English Wiktionary via Wiktextract
Examples
This collection will form the nucleus of a new library.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
3
noun
Meaning 3
The massive, positively charged central part of an atom, made up of protons and neutrons.
Definition source: English Wiktionary via Wiktextract
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
8
noun
Meaning 8
the central structure of the lens that is surrounded by the cortex
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: lens nucleus
Antonyms: none provided
Broader terms: structure, anatomical structure, complex body part, bodily structure, body structure
9
noun
Meaning 9
a part of the cell containing DNA and RNA and responsible for growth and reproduction
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: cell nucleus, karyon
Antonyms: none provided
Broader terms: organelle, cell organelle, cell organ
Narrower terms: pronucleus, subthalamic nucleus
10
noun
Meaning 10
any histologically identifiable mass of neural cell bodies in the brain or spinal cord
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
Broader terms: neural structure
Narrower terms: dentate nucleus
11
noun
Meaning 11
a small group of indispensable persons or things
Definition source: Princeton WordNet 3.0
Examples
five periodicals make up the core of their publishing program
Meaning relationships
Synonyms: core, core group
Antonyms: none provided
Broader terms: set
Narrower terms: cadre
12
noun
Meaning 12
the positively charged dense center of an atom
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
Broader terms: center, centre, midpoint
13
noun
Meaning 13
(astronomy) the center of the head of a comet; consists of small solid particles of ice and frozen gas that vaporizes on approaching the sun to form the coma and tail
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
Broader terms: center, centre, midpoint
History
Etymology
Etymology tree Proto-Italic *knuks Latin nux Latin nucleuslbor. English nucleus Learned borrowing from Latin nucleus (“kernel, core”). The earliest uses refer to the head of a comet and the kernel of a seed, both recorded in Lexicon Technicum in 1704. The sense in atomic physics was coined by British scientist Michael Faraday in 1844 in a theoretical meaning.
Across languages
Translations
250 source translations are retained for this English entry.
Afrikaans:
kern
— core, central part of something
Arabic:
نَوَاة
(nawāh)
— core, central part of something
Armenian:
միջուկ
(miǰuk)
— core, central part of something
Asturian:
nucleu
— core, central part of something
Belarusian:
ядро́
(jadró)
— core, central part of something
Belarusian:
цэнтр
(centr)
— core, central part of something
Bulgarian:
ядро́
(jadró)
— core, central part of something
Catalan:
nucli
— core, central part of something
Chinese Mandarin:
核心
(héxīn)
— core, central part of something
Chinese Mandarin:
核
(hé)
— core, central part of something
Czech:
jádro
— core, central part of something
Czech:
střed
— core, central part of something
Danish:
kerne
— core, central part of something
Dutch:
kern
— core, central part of something
Esperanto:
kerno
— core, central part of something
Finnish:
ydin
— core, central part of something
French:
noyau
— core, central part of something
Galician:
núcleo
— core, central part of something
German:
Kern
— core, central part of something
Greek:
πυρήνας
(pyrínas)
— core, central part of something
Hebrew:
גַּרְעִין
(gar'ín)
— core, central part of something
Hebrew:
ליבה \ לִבָּה
(libá)
— core, central part of something
Hindi:
केंद्र
(kendra)
— core, central part of something
Hindi:
केंद्रीय
(kendrīya)
— core, central part of something
Hungarian:
mag
— core, central part of something
Icelandic:
kjarni
— core, central part of something
Ido:
nukleo
— core, central part of something
Indonesian:
inti
— core, central part of something
Italian:
nucleo
— core, central part of something
Japanese:
核
(kaku)
— core, central part of something
Japanese:
核心
(kakushin)
— core, central part of something
Kazakh:
ядро
(ädro)
— core, central part of something
Korean:
핵심
(haeksim)
— core, central part of something
Korean:
핵
(haek)
— core, central part of something
Central Kurdish:
ناوک
(nawik)
— core, central part of something
Macedonian:
јадро
(jadro)
— core, central part of something
Malay:
teras
— core, central part of something
Māori:
karihi
— core, central part of something
Norwegian Bokmål:
kjerne
— core, central part of something
Norwegian Nynorsk:
kjerne
— core, central part of something
Occitan:
nucli
— core, central part of something
Persian:
هسته
(haste)
— core, central part of something
Polish:
jądro
— core, central part of something
Portuguese:
núcleo
— core, central part of something
Romanian:
nucleu
— core, central part of something
Russian:
ядро́
(jadró)
— core, central part of something
Russian:
центр
(centr)
— core, central part of something
Sanskrit:
केन्द्र
(kendra)
— core, central part of something
Scottish Gaelic:
niùclas
— core, central part of something
Scottish Gaelic:
eitean
— core, central part of something
Scottish Gaelic:
cridhe
— core, central part of something
Serbo-Croatian:
је́згра
— core, central part of something
Serbo-Croatian:
jézgra
— core, central part of something
Slovak:
jadro
— core, central part of something
Slovene:
jedro
— core, central part of something
Spanish:
núcleo
— core, central part of something
Swedish:
kärna
— core, central part of something
Ukrainian:
ядро́
(jadró)
— core, central part of something
Ukrainian:
центр
(centr)
— core, central part of something
Urdu:
مَرکَزَہ
(markaza)
— core, central part of something
Afrikaans:
kern
— initial part which will receive additions
Bulgarian:
заро́диш
(zaródiš)
— initial part which will receive additions
Dutch:
kiem
— initial part which will receive additions
Finnish:
ydin
— initial part which will receive additions
Galician:
núcleo
— initial part which will receive additions
Greek:
πυρήνας
(pyrínas)
— initial part which will receive additions
Hindi:
केंद्र
(kendra)
— initial part which will receive additions
Hindi:
केंद्रीय
(kendrīya)
— initial part which will receive additions
Ido:
nukleo
— initial part which will receive additions
Italian:
nucleo
— initial part which will receive additions
Malay:
teras
— initial part which will receive additions
Polish:
rdzeń
— initial part which will receive additions
Portuguese:
núcleo
— initial part which will receive additions
Romanian:
nucleu
— initial part which will receive additions
Romanian:
miez
— initial part which will receive additions
Russian:
ядро́
(jadró)
— initial part which will receive additions
Scottish Gaelic:
niùclas
— initial part which will receive additions
Scottish Gaelic:
eitean
— initial part which will receive additions
Scottish Gaelic:
cridhe
— initial part which will receive additions
Serbo-Croatian:
је́згра
— initial part which will receive additions
Serbo-Croatian:
jézgra
— initial part which will receive additions
Afrikaans:
nukleus
— physics: massive, positively charged core of an atom
Afrikaans:
atoomkern
— physics: massive, positively charged core of an atom
Albanian:
bërthamë
— physics: massive, positively charged core of an atom
Arabic:
نَوَاة
(nawāh)
— physics: massive, positively charged core of an atom
Armenian:
միջուկ
(miǰuk)
— physics: massive, positively charged core of an atom
Asturian:
nucleu
— physics: massive, positively charged core of an atom
Azerbaijani:
nüvə
— physics: massive, positively charged core of an atom
Belarusian:
ядро́
(jadró)
— physics: massive, positively charged core of an atom
Breton:
kraoñell
— physics: massive, positively charged core of an atom
Bulgarian:
ядро́
(jadró)
— physics: massive, positively charged core of an atom
Burmese:
နျူကလိယ
(nyuka.li.ya.)
— physics: massive, positively charged core of an atom
Catalan:
nucli
— physics: massive, positively charged core of an atom
Chinese Mandarin:
原子核
(yuánzǐhé)
— physics: massive, positively charged core of an atom
Czech:
jádro
— physics: massive, positively charged core of an atom
Dutch:
nucleus
— physics: massive, positively charged core of an atom
Dutch:
atoomkern
— physics: massive, positively charged core of an atom
Estonian:
tuum
— physics: massive, positively charged core of an atom
Finnish:
ydin
— physics: massive, positively charged core of an atom
French:
noyau
— physics: massive, positively charged core of an atom
Galician:
núcleo
— physics: massive, positively charged core of an atom
Georgian:
ბირთვი
(birtvi)
— physics: massive, positively charged core of an atom
German:
Atomkern
— physics: massive, positively charged core of an atom
Greek:
πυρήνας
(pyrínas)
— physics: massive, positively charged core of an atom
Hebrew:
גַּרְעִין
(gar'ín)
— physics: massive, positively charged core of an atom
Hindi:
नाभिक
(nābhik)
— physics: massive, positively charged core of an atom
Hindi:
केंद्रक
(kendrak)
— physics: massive, positively charged core of an atom
Hungarian:
atommag
— physics: massive, positively charged core of an atom
Icelandic:
atómkjarni
— physics: massive, positively charged core of an atom
Icelandic:
frumeindarkjarni
— physics: massive, positively charged core of an atom
Icelandic:
kjarni
— physics: massive, positively charged core of an atom
Ido:
nukleo
— physics: massive, positively charged core of an atom
Indonesian:
inti
— physics: massive, positively charged core of an atom
Irish:
núicléas
— physics: massive, positively charged core of an atom
Italian:
nucleo
— physics: massive, positively charged core of an atom
Japanese:
原子核
(genshikaku)
— physics: massive, positively charged core of an atom
Kazakh:
ядро
(ädro)
— physics: massive, positively charged core of an atom
Khmer:
នយស្តិ
(nĕəʼyŭəh)
— physics: massive, positively charged core of an atom
Khmer:
ណ្វៃយ៉ូ
(nvɨyyou)
— physics: massive, positively charged core of an atom
Korean:
원자핵
(wonjahaek)
— physics: massive, positively charged core of an atom
Central Kurdish:
ناوک
(nawik)
— physics: massive, positively charged core of an atom
Kyrgyz:
ядро
(yadro)
— physics: massive, positively charged core of an atom
Latvian:
kodols
— physics: massive, positively charged core of an atom
Lithuanian:
branduolys
— physics: massive, positively charged core of an atom
Macedonian:
јадро
(jadro)
— physics: massive, positively charged core of an atom
Malay:
nukleus
— physics: massive, positively charged core of an atom
Māori:
karihi
— physics: massive, positively charged core of an atom
Mongolian:
цөм
(cöm)
— physics: massive, positively charged core of an atom
Norwegian Bokmål:
kjerne
— physics: massive, positively charged core of an atom
Norwegian Nynorsk:
kjerne
— physics: massive, positively charged core of an atom
Occitan:
nucli
— physics: massive, positively charged core of an atom
Persian:
هسته
(haste)
— physics: massive, positively charged core of an atom
Polish:
jądro
— physics: massive, positively charged core of an atom
Portuguese:
núcleo
— physics: massive, positively charged core of an atom
Romanian:
nucleu
— physics: massive, positively charged core of an atom
Russian:
ядро́
(jadró)
— physics: massive, positively charged core of an atom
Scottish Gaelic:
niùclas
— physics: massive, positively charged core of an atom
Serbo-Croatian:
је́згра
— physics: massive, positively charged core of an atom
Serbo-Croatian:
jézgra
— physics: massive, positively charged core of an atom
Slovak:
jadro
— physics: massive, positively charged core of an atom
Slovene:
jedro
— physics: massive, positively charged core of an atom
Spanish:
núcleo
— physics: massive, positively charged core of an atom
Swahili:
nyukliasi
— physics: massive, positively charged core of an atom
Swedish:
atomkärna
— physics: massive, positively charged core of an atom
Tagalog:
butod
— physics: massive, positively charged core of an atom
Tagalog:
nukleo
— physics: massive, positively charged core of an atom
Tajik:
ядро
(yadro)
— physics: massive, positively charged core of an atom
Tamil:
அணுக்கரு
(aṇukkaru)
— physics: massive, positively charged core of an atom
Thai:
นิวเคลียส
(niu-klíias)
— physics: massive, positively charged core of an atom
Turkmen:
ýadro
— physics: massive, positively charged core of an atom
Ukrainian:
ядро́
(jadró)
— physics: massive, positively charged core of an atom
Uzbek:
yadro
— physics: massive, positively charged core of an atom
Vietnamese:
hạt nhân
— physics: massive, positively charged core of an atom
Welsh:
niwclews
— physics: massive, positively charged core of an atom
Welsh:
cnewyllyn
— physics: massive, positively charged core of an atom
Afrikaans:
selkern
— cytology: large organelle found in cells
Arabic:
نَوَاة
(nawāh)
— cytology: large organelle found in cells
Belarusian:
ядро́
(jadró)
— cytology: large organelle found in cells
Breton:
kraoñell
— cytology: large organelle found in cells
Bulgarian:
ядро́
(jadró)
— cytology: large organelle found in cells
Catalan:
nucli
— cytology: large organelle found in cells
Chinese Cantonese:
細胞核 /细胞核
(sai3 baau1 hat6)
— cytology: large organelle found in cells
Chinese Mandarin:
細胞核 /细胞核
(xìbāohé)
— cytology: large organelle found in cells
Czech:
jádro
— cytology: large organelle found in cells
Danish:
cellekerne
— cytology: large organelle found in cells
Dutch:
nucleus
— cytology: large organelle found in cells
Dutch:
celkern
— cytology: large organelle found in cells
Esperanto:
nukleo
— cytology: large organelle found in cells
Faroese:
kyknukjarni
— cytology: large organelle found in cells
Finnish:
tuma
— cytology: large organelle found in cells
French:
noyau
— cytology: large organelle found in cells
Galician:
núcleo
— cytology: large organelle found in cells
German:
Zellkern
— cytology: large organelle found in cells
German:
Nukleus
— cytology: large organelle found in cells
Greek:
πυρήνας
(pyrínas)
— cytology: large organelle found in cells
Hindi:
केंद्रक
(kendrak)
— cytology: large organelle found in cells
Hungarian:
sejtmag
— cytology: large organelle found in cells
Icelandic:
frumukjarni
— cytology: large organelle found in cells
Icelandic:
kjarni
— cytology: large organelle found in cells
Ido:
nukleo
— cytology: large organelle found in cells
Indonesian:
inti sel
— cytology: large organelle found in cells
Indonesian:
nukleus
— cytology: large organelle found in cells
Italian:
nucleo
— cytology: large organelle found in cells
Japanese:
細胞核
(saibōkaku)
— cytology: large organelle found in cells
Kazakh:
ядро
(ädro)
— cytology: large organelle found in cells
Khmer:
ណ្វៃយ៉ូ
(nvɨyyou)
— cytology: large organelle found in cells
Korean:
세포핵
(sepohaek)
— cytology: large organelle found in cells
Central Kurdish:
ناوک
(nawik)
— cytology: large organelle found in cells
Macedonian:
јадро
(jadro)
— cytology: large organelle found in cells
Malay:
nukleus
— cytology: large organelle found in cells
Manx:
çheshvean
— cytology: large organelle found in cells
Māori:
karihi
— cytology: large organelle found in cells
Mongolian:
бөөм
(bööm)
— cytology: large organelle found in cells
Mongolian:
ᠪᠥᠭᠡᠮ
(bögem)
— cytology: large organelle found in cells
Navajo:
hinááh bijéí bijéí
— cytology: large organelle found in cells
Norwegian Bokmål:
kjerne
— cytology: large organelle found in cells
Norwegian Bokmål:
cellekjerne
— cytology: large organelle found in cells
Norwegian Nynorsk:
kjerne
— cytology: large organelle found in cells
Norwegian Nynorsk:
cellekjerne
— cytology: large organelle found in cells
Polish:
jądro
— cytology: large organelle found in cells
Polish:
jądro komórkowe
— cytology: large organelle found in cells
Polish:
nukleus
— cytology: large organelle found in cells
Portuguese:
núcleo
— cytology: large organelle found in cells
Romanian:
nucleu
— cytology: large organelle found in cells
Russian:
ядро́
(jadró)
— cytology: large organelle found in cells
Scottish Gaelic:
niùclas
— cytology: large organelle found in cells
Serbo-Croatian:
је́згра
— cytology: large organelle found in cells
Serbo-Croatian:
jézgra
— cytology: large organelle found in cells
Slovak:
jadro
— cytology: large organelle found in cells
Slovene:
jedro
— cytology: large organelle found in cells
Spanish:
núcleo
— cytology: large organelle found in cells
Swahili:
nyukliasi
— cytology: large organelle found in cells
Swedish:
cellkärna
— cytology: large organelle found in cells
Tagalog:
butod
— cytology: large organelle found in cells
Turkish:
çekirdek
— cytology: large organelle found in cells
Turkish:
hücre çekirdeği
— cytology: large organelle found in cells
Turkish:
nükleus
— cytology: large organelle found in cells
Ukrainian:
ядро́
(jadró)
— cytology: large organelle found in cells
Vietnamese:
nhân tế bào
— cytology: large organelle found in cells
Vietnamese:
nhân
— cytology: large organelle found in cells
Welsh:
cnewyllyn
— cytology: large organelle found in cells
Afrikaans:
nukleus
— neuroanatomy: cluster of many neuronal bodies
Dutch:
nucleus
— neuroanatomy: cluster of many neuronal bodies
Hungarian:
mag
— neuroanatomy: cluster of many neuronal bodies
Kazakh:
ядро
(ädro)
— neuroanatomy: cluster of many neuronal bodies
Malay:
nukleus
— neuroanatomy: cluster of many neuronal bodies
Portuguese:
gânglio
— neuroanatomy: cluster of many neuronal bodies
Russian:
ядро́
(jadró)
— neuroanatomy: cluster of many neuronal bodies
Scottish Gaelic:
niùclas
— neuroanatomy: cluster of many neuronal bodies
Serbo-Croatian:
је́згра
— neuroanatomy: cluster of many neuronal bodies
Serbo-Croatian:
jézgra
— neuroanatomy: cluster of many neuronal bodies
Afrikaans:
sillabekern
— linguistics: centre of a syllable
Catalan:
nucli
— linguistics: centre of a syllable
Finnish:
ydin
— linguistics: centre of a syllable
French:
noyau
— linguistics: centre of a syllable
Galician:
núcleo
— linguistics: centre of a syllable
German:
Silbenkern
— linguistics: centre of a syllable
German:
Nukleus
— linguistics: centre of a syllable
German:
Silbengipfel
— linguistics: centre of a syllable
Greek:
πυρήνας
(pyrínas)
— linguistics: centre of a syllable
Hungarian:
szótagmag
— linguistics: centre of a syllable
Icelandic:
kjarni
— linguistics: centre of a syllable
Italian:
nucleo
— linguistics: centre of a syllable
Malay:
teras
— linguistics: centre of a syllable
Persian:
هسته
(haste)
— linguistics: centre of a syllable
Polish:
jądro
— linguistics: centre of a syllable
Portuguese:
núcleo
— linguistics: centre of a syllable
Russian:
ядро́
(jadró)
— linguistics: centre of a syllable
Scottish Gaelic:
niùclas
— linguistics: centre of a syllable
Swedish:
kärna
— linguistics: centre of a syllable
