caffeine

[ka-feen, kaf-een, kaf-ee-in] / kæˈfin, ˈkæf in, ˈkæf i ɪn /

NOUN

coffee

Synonyms

STRONGEST

cappuccino espresso

STRONG

brew decaf decoction demitasse ink java mocha mud perk

WEAK

battery acid café café au lait café noir forty weight hot stuff jamocha joe varnish remover

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

They said that caffeine could affect the results, and gel interferes with the electrodes.

From The Wall Street Journal • Jun. 27, 2026

Many contain large amounts of caffeine, which stimulates the central nervous system and makes you feel more awake.

From BBC • Jun. 22, 2026

Think about when you want to sleep and then have the last caffeine hit eight hours before to help you power through.

From BBC • Jun. 13, 2026

Nur House Cafe — If you’re in need of a caffeine break and something sweet, make time for Nur House Cafe.

From Salon • Jun. 11, 2026

His senses tingled like he’d been injected with caffeine.

From "The Son of Neptune" by Rick Riordan