# methionine

> English word · Noun · IPA /mɪˈθʌɪəniːn/ · frequency rank #51,243

## Definitions
1. A sulphur-containing amino acid, C₅H₁₁NO₂S, in L- and D-forms.
2. A sulphur-containing amino acid, C₅H₁₁NO₂S, in L- and D-forms.

## Etymology
From methyl + thio- + -n- + -ine.

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