: a bitter alkaloid C8H10N4O2 found especially in coffee, tea, cacao, and kola nuts and used medicinally as a stimulant and diuretic
Examples of caffeine in a Sentence
Her doctor told her to avoid caffeine.
Recent Examples on the Web
For those who experience physical or mental side effects from caffeine, Galati suggests turning to decaf coffee, or herbal teas.
—
Hannah Yasharoff, USA TODAY, 9 May 2024
But young people’s proclivity toward heart-thumping drinks extends beyond caffeine.
—Sasha Rogelberg, Fortune, 8 May 2024
See all Example Sentences for caffeine 
Hannah Yasharoff, USA TODAY, 9 May 2024
But young people’s proclivity toward heart-thumping drinks extends beyond caffeine.
—Sasha Rogelberg, Fortune, 8 May 2024
See all Example Sentences for caffeine
These examples are programmatically compiled from various online sources to illustrate current usage of the word 'caffeine.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
Dictionary Entries Near caffeine
Cite this Entry
“Caffeine.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/caffeine. Accessed 15 May. 2024.
Copy CitationKids Definition
caffeine
noun
caf·feine
ka-ˈfēn 
ˈka-ˌfēn
: a bitter stimulating compound found especially in coffee, tea, cacao, and kola nuts
Medical Definition
caffeine
noun
caf·feine
ka-ˈfēn, ˈka-ˌ; ˈkaf-ē-ən
: a bitter alkaloid C8H10N4O2 found especially in coffee, tea, and kola nuts and used medicinally as a stimulant and diuretic
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