柯林斯詞典caffeine /?k?fi?n/ 1. N-UNCOUNT Caffeine is a chemical substance found in coffee, tea, and cocoa, which affects your brain and body and makes you more active. 咖啡因 返回 caffeine劍橋詞典a chemical , found for example in tea and coffee , that is a stimulant (= something that makes people more active ) 咖啡因，咖啡堿 返回 caffeine