名詞 caffeine:

1. a bitter alkaloid found in coffee and tea that is responsible for their stimulating effects
   同義詞：caffein

caffeine 也作 caf.fein

n.（名詞）
A bitter white alkaloid, C8H 0N 4O 2, often derived from tea or coffee and used in medicine chiefly as a mild stimulant and to treat certain kinds of headache.
咖啡因：一種苦味的白色生物堿， C8H 0N 4O 2，通常得自咖啡或茶，在藥品中主要作為溫和興奮劑及治療特定的頭痛病

來源：
German Kaffein from Kaffee [coffee]
德語 Kaffein 源自 Kaffee [咖啡]
or French caféine
或 法語 caféine
both from French café [coffee] * see café
都源自 法語 café [咖啡] *參見 café

【引伸】
caf.feinat.ed