- 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
WordReference Random House Learner's Dictionary of American English © 2026
caf•feine /ˈkæfin/USA pronunciation
n. [uncountable]
WordReference Random House Unabridged Dictionary of American English © 2026- Nutritiona white, bitter chemical, obtained from coffee or tea, used in medicine as a stimulant.
caf•feine
(ka fēn′, kaf′ēn, kaf′ē in),USA pronunciation n. [Chem., Pharm.]
caf•fein•ic
(ka fē′nik, kaf′ē in′ik),USA pronunciation adj.
- Nutritiona white, crystalline, bitter alkaloid, C8H10N4O2, usually derived from coffee or tea: used in medicine chiefly as a nervous system stimulant.
- French caféine, equivalent. to café coffee + -ine -ine2
- 1820–30;
Collins Concise English Dictionary © HarperCollins Publishers::
caffeine, caffein /ˈkæfiːn; ˈkæfɪˌiːn/ n
'caffeine' also found in these entries (note: many are not synonyms or translations):
alkaloid
- caffeinate
- caffeinated
- cola nut
- decaffeinate
- maté
- theine
- xanthine
- APC
- caffeinism
- Darvon Compound
- guarana
- herbal tea
- -ine
- kola nut
- look-alike
- methyltheobromine
- Percodan
- purine
- theobromine
- speed