/ kæfiːn /
ETYM Cf. French caféine. Related to Coffee.
Alkaloid organic substance found in tea, coffee, and kola nuts; it stimulates the heart and central nervous system. When isolated, it is a bitter crystalline compound, C8H10N4O2. Too much caffeine (more than six average cups of tea or coffee a day) can be detrimental to health.
A bitter alkaloid found in coffee and tea that is responsible for their stimulating effects; SYN. caffein.