9 Grammatical Pitfalls


[trip-tuh-fan] /ˈtrɪp təˌfæn/
noun, Biochemistry
an essential amino acid, (C 8 H 6 N)CH 2 CH(NH 2)COOH, colorless, crystalline, and aromatic, released from proteins by tryptic digestion and a precursor of serotonin. Symbol: W.
Abbreviation: Trp;
Also, tryptophane
[trip-tuh-feyn] /ˈtrɪp təˌfeɪn/ (Show IPA)
Origin of tryptophan
1900-05; trypto- (irregular combining form representing Greek trīptós rubbed) + -phan(e) Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
Cite This Source
Examples from the web for tryptophan
  • Serotonin is made from an amino acid called tryptophan, which is the rarest amino acid in our diet.
  • In that case, wait until they slip into a tryptophan-induced coma and then sneak into the den.
  • But he was probably too full tryptophan of to think clearly.
  • Carbohydrates in particular may increase levels of tryptophan and large neutral amino acids.
  • It has even more fiber than the regular variety and respectable amounts of such nutrients as manganese, tryptophan and magnesium.
  • These delicious little packages are dense with nutrients, an excellent source of manganese, copper and tryptophan.
  • tryptophan, which is found in dairy products, may also be helpful.
British Dictionary definitions for tryptophan


an essential amino acid; a component of proteins necessary for growth
Word Origin
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
Cite This Source
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
Cite This Source
tryptophan in Medicine

tryptophan tryp·to·phan (trĭp'tə-fān') or tryp·to·phane (-fān')
Abbr. Try
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.
Cite This Source
tryptophan in Science
An essential amino acid. Chemical formula: C11H12N2O2. See more at amino acid.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source

Word of the Day

Difficulty index for tryptophan

Few English speakers likely know this word

Word Value for tryptophan

Scrabble Words With Friends

Nearby words for tryptophan