amino acid
/əˈminoʊ ˈæsɪd/
"amino-acid" is a 9-letter English headword indexed on PlainSpell.
The verdict
“amino acid” is uncommon English (outside the top frequency list), classed as a noun. The kind of spelling people second-guess.
- Unranked
- below top-frequency English
- 10
- letters
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Any organic compound containing both an amino and a carboxylic acid functional group.
| Property | Value |
|---|---|
| Headword | amino acid |
| Language | English |
| Part of speech | Noun |
| IPA | /əˈminoʊ ˈæsɪd/ |
| Letters | 10 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “amino acid” sits in English frequency
Rare enough to double-check
amino acid is uncommon English outside the top frequency list, classed as anoun, transcribed /əˈminoʊ ˈæsɪd/. Rarity is why readers land here mid-draft. 2 senses are on record.
No generated misspelling entries exist for amino acid in our index, a straightforward case of a spelling with little room for common typos. Our dataset records no confusable match here, which typically means the spelling is too distinctive to be mistaken for another word.
Etymologically, the entry records: See amine and acid. Likely a calque of German Aminosäure, which is attested earlier. The correct English form is amino acid, spelled A-M-I-N-O- -A-C-I-D.
Definition
- 1Any organic compound containing both an amino and a carboxylic acid functional group.
- 2Any of the twenty naturally occurring α-amino acids (having the amino, and carboxylic acid groups on the same carbon atom), and a variety of side chains, that combine, via peptide bonds, to form proteins.
Etymology
See amine and acid. Likely a calque of German Aminosäure, which is attested earlier.
Synonyms
This word in other languages
Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA). See the methodology for how each field is sourced and updated.
Frequently Asked Questions
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Using “amino acid”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is A-M-I-N-O- -A-C-I-D - every other letter order is a misspelling in standard orthography.
- Say it as /əˈminoʊ ˈæsɪd/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
- Browse more English words and confusable pairs in the same reference. English words
Data Source
Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.