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:/ˈpɹəʊ.tɒn/
US:/ˈpɹoʊ.tɑn/
US:Recorded audio is listed in the source snapshot.
rhymes with (Received Pronunciation) -əʊtɒn
rhymes with (US) -oʊtɑn
CMU ARPABET:P R OW1 T AA2 N
Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.
1
noun
Meaning 1
A positively charged subatomic particle forming part of the nucleus of an atom and determining the atomic number of an element, composed of two up quarks and a down quark.
Definition source: English Wiktionary via Wiktextract
A positively charged subatomic particle forming part of the nucleus of an atom and determining the atomic number of an element, composed of two up quarks and a down quark.
The atomic nucleus of protium (hydrogen-1)
Definition source: English Wiktionary via Wiktextract
Definition source: English Wiktionary via Wiktextract
Usage: obsolete
Topics: anatomy, medicine, sciences
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: primordium
Antonyms: none provided
4
noun
Meaning 4
a stable particle with positive charge equal to the negative charge of an electron
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
Broader terms: nucleon
Narrower terms: hydrogen ion
History
Etymology
Etymology tree Proto-Indo-European *per-der.? Proto-Indo-European *per-der.? Proto-Indo-European *pér Proto-Indo-European *-o Proto-Indo-European *próder. Ancient Greek πρό (pró) Ancient Greek -ᾰτος (-ătos) Ancient Greek πρῶτον (prôton)lbor. English proton Learned borrowing from Ancient Greek πρῶτον (prôton), neuter of πρῶτος (prôtos, “first”). (physics): Coined by New Zealand-British scientist Ernest Rutherford in 1920, in analogy with electron (1891), and with an additional intention of honoring English chemist William Prout. Analyzable as proto- + -on (anatomy): A translation of German Anlage (“fundamental thing”) based on Aristotle’s phrase ἡ πρώτη οὐσία τὸ πρῶτον (hē prṓtē ousía tò prôton).
Across languages
Translations
62 source translations are retained for this English entry.
