caffeine
or caf·fein
[ka-feen, kaf-een, kaf-ee-in]
- a white, crystalline, bitter alkaloid, C8H10N4O2, usually derived from coffee or tea: used in medicine chiefly as a nervous system stimulant.
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Origin of caffeine
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for caffeine
Contemporary Examples
The Pentagon security reviewers must have been suffering a dearth of caffeine or sleep.
‘They Don’t Call It SEAL Team 6-Year-Old for Nothing’: Commandos Clash Over Tell-All BookKimberly Dozier
November 3, 2014
The story gets out that Obama skipped his usual afternoon dose of caffeine heading toward the U.N. meeting.
This clean source of caffeine is the next noble, and healthy, substitute for your daily cup of coffee.
Bye Bye Latté, Hello Guayusa: Why The Amazon Holds the Secret to a Cleaner, Healthier CaffeineBrandon Presser
August 29, 2014
A “caffeine nap,” or a quick cup of something caffeinated followed by a nap, outperforms both a nap or caffeine independently.
Einöther authored the most comprehensive review of research on caffeine to date.
Historical Examples
Kola drinks owe their vogue to the caffeine which they contain.
Alcohol: A Dangerous and Unnecessary Medicine, How and WhyMartha M. Allen
Coffee owes its stimulating and refreshing qualities to caffeine.
Six Cups of CoffeeMaria Parloa
The residue left in the retort is a mixture of caffeine and a resinous substance containing chlorophyll.
Caffeine separated by Oudry, and quinin by Pelletier and Caventou.
It's loaded with caffeine—a drug that is both a strong stimulant and a diuretic.
The Ethical EngineerHenry Maxwell Dempsey
caffeine
caffein
- 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)
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Word Origin
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
Online Etymology Dictionary, © 2010 Douglas Harper
caffeine
- 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.
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The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
caffeine
[kă-fēn′]
- 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.
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The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.