[ trip-tuh-fan ]
/ ˈtrɪp təˌfæn /

noun Biochemistry.

an essential amino acid, (C8H6N)CH2CH(NH2)COOH, colorless, crystalline, and aromatic, released from proteins by tryptic digestion and a precursor of serotonin. Abbreviation: Trp; Symbol: W

Nearby words

  1. trypophobia,
  2. trypsin,
  3. trypsinogen,
  4. tryptamine,
  5. tryptic,
  6. tryptophan 2,3-dioxygenase,
  7. tryptophanase,
  8. tryptophane,
  9. tryptophanuria,
  10. trysail

Also tryp·to·phane [trip-tuh-feyn] /ˈtrɪp təˌfeɪn/.

Origin of tryptophan

1900–05; trypto- (irregular combining form representing Greek trīptós rubbed) + -phan(e) Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for tryptophan

British Dictionary definitions for tryptophan


/ (ˈtrɪptəˌfæn) /


an essential amino acid; a component of proteins necessary for growth

Word Origin for tryptophan

C20: from trypt (ic) + -o + -phan variant of -phane

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for tryptophan



also tryptophane, complex amino acid, 1890, coined in German from trypto-, taken as a comb. form of tryptic "by trypsin," + Greek phainein "to appear" (see phantasm).

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for tryptophan


[ trĭptə-făn′ ]


An essential amino acid formed from proteins during the digestive process by the action of proteolytic enzymes.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for tryptophan


[ trĭptə-făn′ ]

An essential amino acid. Chemical formula: C11H12N2O2. See more at amino acid.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.