Standard Lemma guide

tryptophan

noun · 2 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.

  • UK: /ˈtɹɪptə(ʊ)fæn/
  • UK: Recorded audio is listed in the source snapshot.

1

noun

Meaning 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.

Definition source: English Wiktionary via Wiktextract

Usage: countable, uncountable

Topics: biochemistry, biology, chemistry, microbiology, natural-sciences, physical-sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

an amino acid that occurs in proteins; is essential for growth and normal metabolism; a precursor of niacin

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: tryptophane

Antonyms: none provided

Broader terms: essential amino acid

History

Etymology

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

Across languages

Translations

19 source translations are retained for this English entry.

  • Bulgarian: триптофан (triptofan) — essential amino acid
  • Catalan: triptòfan — essential amino acid
  • Chinese Mandarin: 色氨酸 (sè'ānsuān) — essential amino acid
  • Czech: tryptofan — essential amino acid
  • Finnish: tryptofaani — essential amino acid
  • French: tryptophane — essential amino acid
  • Galician: triptofano — essential amino acid
  • German: Tryptophan — essential amino acid
  • Greek: θρυπτοφάνη (thryptofáni) — essential amino acid
  • Hungarian: triptofán — essential amino acid
  • Japanese: トリプトファン (toriputofan) — essential amino acid
  • Persian: تریپتوفان (teriptofân) — essential amino acid
  • Polish: tryptofan — essential amino acid
  • Portuguese: triptofano — essential amino acid
  • Romanian: triptofan — essential amino acid
  • Russian: триптофа́н (triptofán) — essential amino acid
  • Spanish: triptófano — essential amino acid
  • Swedish: tryptofan — essential amino acid
  • Thai: ทริปโตเฟน — essential amino acid