# threonine

> English word · Noun · frequency rank #69,511

## Definitions
1. An essential amino acid C₄H₉NO₃ found in most animal proteins.

## Etymology
From threose.

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