# ammonium

> English word · Noun · IPA /əˈmoʊni.əm/ · frequency rank #27,717

## Definitions
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

## Etymology
From New Latin ammōnium. Equivalent to ammonia + -ium.

## Easily confused with
- **ammonia** (https://plainspell.com/en/vs/ammonia-vs-ammonium)

## Common misspellings (9)
`ammnoium`, `ammoinum`, `ammonimu`, `ammoniumm`, `ammonnium`, `ammonuim`, `amomnium`, `amonium`, `mamonium`

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/ammonium