ammonium
/əˈmoʊni.əm/noun
ammonium is spelled A-M-M-O-N-I-U-M: 8 letters and 4 syllables. It appears 1.1 times per million words in written English, the 27,820th most frequent word form (wordfreq, 2021 data). As a noun, ammonium means “The univalent NH₄⁺ cation, derived by the protonation of ammonia” (English Wiktionary, September 2026). The plural of ammonium is ammoniums.
How many letters and syllables are in ammonium?
| Letters | 8: A-M-M-O-N-I-U-M |
|---|---|
| Syllables | 4 (from its American pronunciation) |
| In writing | 1.1 times per million words; the 27,820th most frequent word form |
| Wrong spellings searched | none measured in search |
| Rhymes with |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation and the CMU Pronouncing Dictionary; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media); rhymes and same-letter words are computed by PlainSpell from its own word list.
How common is ammonium?
Ammonium appears 1.1 times per million words in written English, the 27,820th most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you pronounce ammonium?
- US /əˈmoʊni.əm/
Ammonium has 4 syllables (counted from its American pronunciation in the CMU Pronouncing Dictionary).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: LL-Q1860_(eng)-Vealhurl-ammonium.wav, Wikimedia Commons (author and licence on each file's page).
What rhymes with ammonium?
The 12 most written words on PlainSpell end in the same sounds as ammonium from its last stressed vowel (/oʊniəm/):
- pandemonium
- polonium
- harmonium
- pancuronium
- vecuronium
- hydronium
- neutronium
- rocuronium
- pandamonium
- tetraethylammonium
- onium
- suxamethonium
Computed by PlainSpell from the pronunciations in the English Wiktionary (dump of September 2, 2026): a rhyme shares every sound from the last stressed vowel to the end; ordered by written frequency (wordfreq 3.1).
Forms of ammonium
- ammoniums plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does ammonium mean?
The meanings the English Wiktionary records, quoted as written there (source below).
noun
- 1
The univalent NH₄⁺ cation, derived by the protonation of ammonia
- 2
Any similar cation formed by replacing one or more hydrogen atoms with alkyl or aryl radicals
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Ammonium in Spanish, French, German and Portuguese
In the sense univalent NH4+ cation:
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.
Where does ammonium come from?
From New Latin ammōnium. Equivalent to ammonia + -ium.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).