[his-ti-deen, -din]
noun Biochemistry.
  1. an essential amino acid, C3H3N2CH2CH(NH2)COOH, that is a constituent of proteins and is important as the iron-binding site in hemoglobin. Abbreviation: His; Symbol: H
Also his·ti·din [his-ti-din] /ˈhɪs tɪ dɪn/.

Origin of histidine

First recorded in 1895–1900; hist- + -id3 + -ine2
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for histidine


  1. a nonessential amino acid that occurs in most proteins: a precursor of histamine
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 histidine

complex amino acid, 1896, from German histidin; see histo- + chemical suffix -idine.

Online Etymology Dictionary, © 2010 Douglas Harper

histidine in Medicine


[hĭstĭ-dēn′, -dĭn]
  1. An amino acid that is essential for tissue growth and repair.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

histidine in Science


  1. An amino acid that is essential for children but not for adults. Chemical formula: C6H9N3O2.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.