caffeine
caffeine
caf·feine / ˌkæˈfin ; ˈkæfi:n /noun U
1. a substance in tea, coffee, and some other drinks that makes you feel more active咖啡因，咖啡碱;
⇒decaffeinated:
•Avoid caffeine (=drinks with caffeine) before bedtime.睡觉前不要喝含有咖啡因的饮料。
•a caffeine-free cola不含咖啡因的可乐
—caffeinated / ˈkæfinetɪd ; ˈkæfəneɪtəd / adj.