Definition of caffeine in English:


Syllabification: caf·feine
Pronunciation: /kaˈfēn
, ˈkafˌēn


A crystalline compound that is found especially in tea and coffee plants and is a stimulant of the central nervous system.
  • An alkaloid, 1,3,7-trimethylxanthine; chemical formula: C8H10N4O2
More example sentences
  • The stimulant effects of caffeine in coffee are well known to help improve energy and alertness.
  • They have a similar effect to tea or coffee, since they contain the same alkaloid, caffeine.
  • In flowering plant pollen tubes, caffeine disrupts vesicle zonation at the tip and stops elongation.


mid 19th century: from French caféine, from café 'coffee'.

Definition of caffeine in:

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