noun · 4 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
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Received-Pronunciation:/ˌætəˈmɪsɪti/
UK:Recorded audio is listed in the source snapshot.
General-American:/ˌætəˈmɪsɪti/
General-American:[-ɾə-]
General-American:[-ɾi]
rhymes with -ɪsɪti
1
noun
Meaning 1
The number of atoms in a molecule.
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
Synonym of valence (“the combining capacity of an atom, functional group, or radical determined by the number of atoms of hydrogen with which it will unite, or the number of electrons that it will gain, lose, or share when it combines with other atoms, etc.”).
Definition source: English Wiktionary via Wiktextract
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
4
noun
Meaning 4
The quality or state of being atomic.
Definition source: English Wiktionary via Wiktextract
Usage: uncountable
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
History
Etymology
Etymology tree Proto-Indo-European *né Proto-Indo-European *n̥- Proto-Hellenic *ə- Ancient Greek ἀ- (a-) Proto-Indo-European *temh1- Proto-Indo-European *-né- Ancient Greek τέμνω (témnō) Proto-Indo-European *-ós Proto-Hellenic *-ós ▲ Ancient Greek -ος (-os)influ. Ancient Greek -ός (-ós) Ancient Greek *τομός (*tomós) Ancient Greek ἄτομος (átomos)bor. Latin atomusbor. Middle French athomebor. Middle English attome English atom Proto-Indo-European *-ikos Proto-Italic *-ikos Latin -icuslbor. Old French -iquebor. Middle English -ik English -ic English atomic Proto-Indo-European *-teh2 Proto-Indo-European *-ts Proto-Indo-European *-teh2ts Latin -itāsder. Old French -itebor. Middle English -ite English -ity English atomicity From atomic + -ity.
Across languages
Translations
12 source translations are retained for this English entry.
Finnish:
atomien lukumäärä
— number of atoms in a molecule
Finnish:
atomisuus
— state of a system in which either all stages complete or none complete
Finnish:
jakamattomuus
— state of a system in which either all stages complete or none complete
Catalan:
atomicitat
— quality or state of being atomic
Finnish:
atomisuus
— quality or state of being atomic
Finnish:
jakamattomuus
— quality or state of being atomic
French:
atomicité
— quality or state of being atomic
German:
Atomizität
— quality or state of being atomic
German:
Atomarität
— quality or state of being atomic
German:
Atomigkeit
— quality or state of being atomic
Irish:
adamhacht
— quality or state of being atomic
Spanish:
atomicidad
— quality or state of being atomic