tryptophan

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

• (UK) IPA^(key): /ˈtɹɪptə(ʊ)fan/

tryptophan (countable and uncountable, plural tryptophans)

1. (biochemistry) An essential amino acid having an indole side chain; it is present in many foods, especially chocolate, oats, bananas 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.
   • 1999, Matt Ridley, Genome, Harper Perennial 2004, p. 169:

     The quickest way to raise serotonin levels again is to send more tryptophan into the brain, because serotonin is made from tryptophan.

• Trp
• tryp