: 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
The bladder urgency and frequency that millennial women are experiencing can be caused, in part, by irritants like caffeine, alcohol, seltzer water, and chocolate, says McGurk, and also poor water intake and prolonged sitting.
—
Fiorella Valdesolo, Vogue, 19 Apr. 2024
It’s formulated with plenty of caffeine to de-puff tired bags, peptides to improve the appearance of dark circles, and other skin-friendly ingredients to reduce those pesky signs of long travel days by leaving you fresh, energized, and refreshed.
—Alexandra Domrongchai, Travel + Leisure, 6 Apr. 2024
The caffeine content of the drinks is also unknown, as were the specific types of artificial sweeteners used in the beverages consumed.
—Julia Landwehr, Health, 26 Mar. 2024
Some are fans of green tea, or calming chamomile, while others prefer the caffeine kick of black tea.
—Clare Mulroy, USA TODAY, 18 Mar. 2024
Stimulants such as caffeine are often considered the most effective ingredients in thermogenic fat burners like PrimeShred and Instant Knockout Cut.
—Robert James and, Miami Herald, 8 Apr. 2024
Jitters and anxiety are usually limited to caffeine: Lots of fat burners contain caffeine in high doses, so check the dose aligns with your tolerance before taking.
—Discover Magazine, 3 Apr. 2024
Certainly, a drink stuffed with huge amounts of caffeine will be energizing.
—Yasmin Tayag, The Atlantic, 28 Mar. 2024
Caffeine Control: Limit caffeine consumption to before 12 p.m. for better sleep quality.
—Maryal Miller Carter, USA TODAY, 25 Mar. 2024
Fiorella Valdesolo, Vogue, 19 Apr. 2024
It’s formulated with plenty of caffeine to de-puff tired bags, peptides to improve the appearance of dark circles, and other skin-friendly ingredients to reduce those pesky signs of long travel days by leaving you fresh, energized, and refreshed.
—Alexandra Domrongchai, Travel + Leisure, 6 Apr. 2024
The caffeine content of the drinks is also unknown, as were the specific types of artificial sweeteners used in the beverages consumed.
—Julia Landwehr, Health, 26 Mar. 2024
Some are fans of green tea, or calming chamomile, while others prefer the caffeine kick of black tea.
—Clare Mulroy, USA TODAY, 18 Mar. 2024
Stimulants such as caffeine are often considered the most effective ingredients in thermogenic fat burners like PrimeShred and Instant Knockout Cut.
—Robert James and, Miami Herald, 8 Apr. 2024
Jitters and anxiety are usually limited to caffeine: Lots of fat burners contain caffeine in high doses, so check the dose aligns with your tolerance before taking.
—Discover Magazine, 3 Apr. 2024
Certainly, a drink stuffed with huge amounts of caffeine will be energizing.
—Yasmin Tayag, The Atlantic, 28 Mar. 2024
Caffeine Control: Limit caffeine consumption to before 12 p.m. for better sleep quality.
—Maryal Miller Carter, USA TODAY, 25 Mar. 2024
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 1 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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