This shows grade level based on the word's complexity.
caffeine
[ ka-feen, kaf-een, kaf-ee-in ]
/ kæˈfin, ˈkæf in, ˈkæf i ɪn /
See the most commonly confused word associated with theobromine
Save This Word!
This shows grade level based on the word's complexity.
noun
Chemistry, Pharmacology. a white, crystalline, bitter alkaloid, C8H10N4O2, usually derived from coffee or tea: used in medicine chiefly as a nervous system stimulant.
Informal. a drink, usually coffee or tea, containing this stimulant:We sipped our caffeine on the balcony with its views of sea stacks, rocky coves, and the ever-changing ocean.
COMPARE MEANINGS
Click for a side-by-side comparison of meanings. Use the word comparison feature to learn the differences between similar and commonly confused words.
QUIZ
CAN YOU ANSWER THESE COMMON GRAMMAR DEBATES?
There are grammar debates that never die; and the ones highlighted in the questions in this quiz are sure to rile everyone up once again. Do you know how to answer the questions that cause some of the greatest grammar debates?
Question 1 of 7
Which sentence is correct?
Rarely caf·fein .
Origin of caffeine
OTHER WORDS FROM caffeine
caf·fein·ic [ka-fee-nik, kaf-ee-in-ik], /kæˈfi nɪk, ˌkæf iˈɪn ɪk/, adjectivenon·caf·feine, nounnon·caf·fein·ic, adjectiveWords nearby caffeine
cafetiere, cafetorium, caff, caffeinate, caffeinated, caffeine, caffeinism, caffè latte, caffè macchiato, CAFO, cafone
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use caffeine in a sentence
British Dictionary definitions for caffeine
caffeine
caffein
/ (ˈkæfiːn, ˈkæfɪˌiːn) /
noun
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
Scientific definitions for caffeine
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.
The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.