noun · 2 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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kătʹ-ī-ən
/ˈkætˌaɪ.ən/
/ˈkætˌaɪ.ɑn/
Southern-England:Recorded audio is listed in the source snapshot.
CMU ARPABET:K AE1 T AY2 AH0 N
Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.
1
noun
Meaning 1
A positively charged ion: one that would be attracted to the cathode in electrolysis.
Definition source: English Wiktionary via Wiktextract
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: anion
Broader terms: ion
2
noun
Meaning 2
a positively charged ion
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
Broader terms: ion
Narrower terms: hydrogen ion, diazonium
History
Etymology
Learned borrowing from Ancient Greek κᾰτῐόν (kătĭón), neuter present participle of κᾰ́τειμῐ (kắteimĭ, “to go down, come down”), from κᾰτᾰ- (kătă-, “downwards, down, cata-”) + εἶμῐ (eîmĭ, “to go, come”). Coined by English polymath William Whewell in 1834 for Michael Faraday, who introduced it later that year. By surface analysis, cat(a)- + ion.
Across languages
Translations
40 source translations are retained for this English entry.
