follow Dictionary.com

Why is the ninth month called September?

caffeine

[ka-feen, kaf-een, kaf-ee-in] /kæˈfin, ˈkæf in, ˈkæf i ɪn/
noun, Chemistry, Pharmacology
1.
a white, crystalline, bitter alkaloid, C 8 H 10 N 4 O 2 , usually derived from coffee or tea: used in medicine chiefly as a nervous system stimulant.
Also, caffein.
Origin
1820-1830
1820-30; < French caféine, equivalent to café coffee + -ine -ine2
Related forms
caffeinic
[ka-fee-nik, kaf-ee-in-ik] /kæˈfi nɪk, ˌkæf iˈɪn ɪk/ (Show IPA),
adjective
noncaffeine, noun
noncaffeinic, adjective
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source
Examples for caffeine
  • caffeine is a substance that is found in certain plants.
  • Sometimes that requires a caffeine source or several sometimes that requires a trip to the gym.
  • It could be a close vote, but taxing caffeine has unfortunate precedents.
  • Alkaloids, which include caffeine and nicotine, are a highly diverse group of chemicals with many unusual properties.
  • For many coffee lovers, their precious beverage comes with an unwanted ingredient: caffeine.
  • Choose from molecular earrings, a caffeine molecule necklace, or a circuit board pendant.
  • Some people can't start their day without a caffeine jolt from a cup of coffee.
  • caffeine is a substance that exists naturally in certain plants.
  • caffeine could be added to keep drinkers awake during boring dinner parties.
  • So much coffee is consumed that scientists have found that caffeine permeates the local seawater.
British Dictionary definitions for caffeine

caffeine

/ˈkæfiːn; ˈkæfɪˌiːn/
noun
1.
a white crystalline bitter alkaloid responsible for the stimulant action of tea, coffee, and cocoa: a constituent of many tonics and analgesics. Formula: C8H10N4O2 See also xanthine (sense 2)
Word Origin
C19: from German Kaffein, from Kaffeecoffee
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 caffeine
n.

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
Cite This Source
caffeine in Medicine

caffeine caf·feine or caf·fein (kā-fēn', kāf'ēn', kāf'ē-ĭn)
n.
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.
Cite This Source
caffeine in Science
caffeine
  (kā-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.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source

Word of the Day

Difficulty index for caffeine

Some English speakers likely know this word

Word Value for caffeine

16
18
Scrabble Words With Friends