Meaning of “caffeine” in the English Dictionary

american-english dictionary

"caffeine" in British English

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caffeinenoun [ U ]

uk /ˈkæf.iːn/ us /ˈkæf.iːn/

Examples from literature

  • Caffeine wakes us up and gives us energy. 
  • Many people like tea and coffee because of the caffeine in these drinks. 
  • Effects of Tea and Coffee. —In addition to the stimulating agent caffeine, tea and coffee contain a bitter, astringent substance, known as tannin. 
  • In chemical composition caffeine closely resembles a waste, called uric acid, and in the body is converted into this substance. 
  • Tea and coffee contain a drug, called caffeine, which acts upon the nervous system and which may, on this account, interfere with the proper control of the heart. 
  • The first trial to combat or prevent this drowsiness was made with caffeine. 
  • They are usually so addicted to caffeine, cigarettes, alcohol, and so forth, that when they had fasted, even briefly, their bodies were forced to dip into highly-polluted fat reserves while simultaneously the body begins withdrawal. 

(Definition of “caffeine” from the Cambridge Advanced Learner’s Dictionary & Thesaurus © Cambridge University Press)

"caffeine" in American English

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caffeinenoun [ U ]

us /kæˈfin, ˈkæf·in/

a chemical found in coffee and tea that is a stimulant (= something that tends to make you more active)

(Definition of “caffeine” from the Cambridge Academic Content Dictionary © Cambridge University Press)