[thahy-uh-min, -meen]
noun Biochemistry.
  1. a white, crystalline, water-soluble compound of the vitamin-B complex, containing a thiazole and a pyrimidine group, C12H17ClN4OS, essential for normal functioning of the nervous system, a deficiency of which results chiefly in beriberi and other nerve disorders: occurring in many natural sources, as green peas, liver, and especially the seed coats of cereal grains, the commercial product of which is chiefly synthesized in the form of its chloride (thiamine chloride or thiamine hydrochloride) for therapeutic administration, or in nitrate form (thiamine mononitrate) for enriching flour mixes.
Also thi·a·min [thahy-uh-min] /ˈθaɪ ə mɪn/.

Origin of thiamine

First recorded in 1905–10; thi- + amine
Also called vitamin B1, aneurin, aneurine. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for thiamin

Historical Examples of thiamin

  • I've been fighting shock with thiamin for the last hour, but I don't think I can hold out much longer.

    Bear Trap

    Alan Edward Nourse

British Dictionary definitions for thiamin


thiamin (ˈθaɪəmɪn)

  1. biochem a soluble white crystalline vitamin that occurs in the outer coat of rice and other grains. It forms part of the vitamin B complex and is essential for carbohydrate metabolism: deficiency leads to nervous disorders and to the disease beriberi. Formula: C 12 H 17 ON 4 SCl.H 2 OAlso: vitamin B 1, aneurin

Word Origin for thiamine

C20: thio- + (vit) amin
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 thiamin

also thiamine, alternative name for vitamin B1, 1937, coined by U.S. chemist Dr. Robert R. Williams (1886-1965) from thio-, indicating the presence of sulfur, comb. form of Greek theion "sulfur," + amine, indicating the amino group. Or the second element might be from vitamin.

Online Etymology Dictionary, © 2010 Douglas Harper

thiamin in Medicine


[thīə-mĭn, -mēn′]
  1. A vitamin of the vitamin B complex, found in meat, yeast, and the bran coat of grains, and necessary for carbohydrate metabolism and normal neural activity.vitamin B1
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

thiamin in Science


  1. A water-soluble pyrimidine derivative belonging to the vitamin B complex that is important in carbohydrate metabolism and normal activity of the nervous system. It is found in pork, organ meats, whole grain cereals, legumes, and nuts. Deficiency of thiamine in the diet results in beriberi. Also called vitamin B1. Chemical formula: C12H17ClN4OS.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.