or caf·fein

[ka-feen, kaf-een, kaf-ee-in]

noun Chemistry, Pharmacology.

a white, crystalline, bitter alkaloid, C8H10N4O2, usually derived from coffee or tea: used in medicine chiefly as a nervous system stimulant.

Origin of caffeine

1820–30; < French caféine, equivalent to café coffee + -ine -ine2
Related formscaf·fein·ic [ka-fee-nik, kaf-ee-in-ik] /kæˈfi nɪk, ˌkæf iˈɪn ɪk/, adjectivenon·caf·feine, nounnon·caf·fein·ic, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for caffeine

cappuccino, espresso, perk, mud, brew, java, decaf, decoction, mocha, demitasse, ink, joe

Examples from the Web for caffeine

Contemporary Examples of caffeine

Historical Examples of caffeine

British Dictionary definitions for caffeine




a white crystalline bitter alkaloid responsible for the stimulant action of tea, coffee, and cocoa: a constituent of many tonics and analgesics. Formula: C 8 H 10 N 4 O 2See also xanthine (def. 2)

Word Origin for caffeine

C19: from German Kaffein, from Kaffee coffee
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 caffeine

trimethyl-derivative of xanthine, 1830, from German Kaffein, coined by chemist F.F. Runge (1795-1867), apparently from German Kaffee "coffee" (see coffee) + chemical suffix -ine (2) (German -in). The form of the English word may be via French caféine.

Online Etymology Dictionary, © 2010 Douglas Harper

caffeine in Medicine



A bitter white alkaloid often derived from tea or coffee and used chiefly as a mild stimulant and in the treatment of certain kinds of headache.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

caffeine in Science



A bitter white alkaloid found in tea leaves, coffee beans, and various other plant parts. It is a mild stimulant. Caffeine is a xanthine and similar in structure to theobromine and theophylline. Chemical formula: C8H10N4O2.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.