# tryptophan

> English word · Noun · IPA /ˈtɹɪptə(ʊ)fæn/ · frequency rank #47,977

## Definitions
1. An essential amino acid with an indole side chain; present in many foods, especially chocolate, oats, banana and milk; it is essential for normal growth and development and is the precursor of serotonin and niacin; any specific form of this compound, or any derivative of it.

## Etymology
From German Tryptophan, from Ancient Greek φαίνω (phaínō, “to appear”).

## Common misspellings (17)
`rtyptophan`, `trpytophan`, `trryptophan`, `trypotphan`, `trypptophan`, `tryptohpan`, `tryptopahn`, `tryptophann`, `tryptophhan`, `tryptophna`, `tryptopphan`, `tryptpohan`, `trypttophan`, `trytpophan`, `tryyptophan`, `ttryptophan`, `tyrptophan`

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