caf ‧ feine /ˈkæfiːn $ kæˈfiːn/ BrE AmE noun [uncountable]
[ Date: 1800-1900 ; Language: German ; Origin: kaffein , from kaffee 'coffee' , from French café ]
a substance in tea, coffee, and some other drinks that makes you feel more active ⇨ decaffeinated :
Avoid caffeine (=drinks with caffeine) before bedtime.
a caffeine-free cola
—caffeinated /ˈkæfəneɪtəd, ˈkæfɪneɪtəd/ adjective