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Showing results for caffeine.
Definitions

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.

To investigate this idea, the scientists designed a controlled experiment using different caffeine levels.

From Science Daily • Apr. 18, 2026

There, they encountered a drop of sugar solution containing 0, 25 ppm, 250 ppm, or 2,000 ppm of caffeine.

From Science Daily • Apr. 18, 2026

The people who gather in this small room on the eighth floor of the New York Stock Exchange look like a group of middle-aged caffeine addicts.

From The Wall Street Journal • Apr. 15, 2026

Sales of energy drinks and crafted sodas are booming as Americans look beyond coffee and tea to get their caffeine fix and treat themselves.

From The Wall Street Journal • Apr. 13, 2026

We all knew the effect caffeine had on Ms. Gruwell.

From "The Freedom Writers Diary" by The Freedom Writers