caffeine

noun
caf·​feine | \ ka-ˈfēn How to pronounce caffeine (audio) , ˈka-ˌfēn\

Definition of caffeine

: a bitter alkaloid C8H10N4O2 found especially in coffee, tea, cacao, and kola nuts and used medicinally as a stimulant and diuretic

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Examples of caffeine in a Sentence

Her doctor told her to avoid caffeine.
Recent Examples on the Web Coca-Cola Energy has 114 mg of caffeine in each 12-ounce serving. Danielle Wiener-bronner, CNN, "Coca-Cola Energy is coming to the United States," 1 Oct. 2019 There is a limit to this pricing power, though, as competing coffee chains, doughnut shops and fast-food establishments have rushed to offer caffeine addicts a cheaper fix. Spencer Jakab, WSJ, "Overly Grande Expectations for Starbucks," 1 Nov. 2018 Rest assured, however, there are products out there that are specifically formulated to bring temporary relief for puffy eyes, Stevenson says, such as products with caffeine, which can help constrict the blood vessels. Shannon Romanowski, SELF, "Does Preparation H Actually Help Treat Puffy Eyes?," 28 Dec. 2018 The fermentation process takes out most of the sugar and caffeine. Lydia Gerike, courant.com, "Kombucha comes to Connecticut: Brewers help introduce a new kind of drink to the state," 10 Aug. 2019 The sugar and caffeine propelled us through a three-hour visit . Los Angeles Times, "Scotland a foodie haven? ’Tis true. And so is this: Haggis is kind of great," 20 July 2019 Avoiding alcohol use — alcohol and even caffeine can actually dehydrate the body. NBC News, "Don't fry: 3 stages of heat stroke you need to know," 19 July 2019 The space hums with an up-all-night youthful energy (no doubt aided by copious amounts of sugar and caffeine), and the coffee jelly in particular is a textural delight. Jordan Michelman, latimes.com, "What’s brewing in Chinatown: a microguide to four unique coffee bars," 21 June 2019 Examples included antibiotics, anti-inflammatory (ibuprofen), anti-depressants, anti-diabetics, stimulants (caffeine), and reproductive and thyroid hormones. David Taylor, Houston Chronicle, "Cleveland PD offering safe place to dispose of drugs," 13 Sep. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'caffeine.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of caffeine

circa 1823, in the meaning defined above

History and Etymology for caffeine

German Kaffein, from Kaffee coffee, from French café

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Statistics for caffeine

Last Updated

18 Nov 2019

Time Traveler for caffeine

The first known use of caffeine was circa 1823

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More Definitions for caffeine

caffeine

noun
How to pronounce caffeine (audio)

English Language Learners Definition of caffeine

: a substance that is found especially in coffee and tea and that makes you feel more awake

caffeine

noun
caf·​feine | \ ka-ˈfēn How to pronounce caffeine (audio) , ˈka-ˌfēn\

Kids Definition of caffeine

: a substance found especially in coffee and tea that makes a person feel more awake

caffeine

noun
caf·​feine | \ ka-ˈfēn, ˈka-ˌ; ˈkaf-ē-ən How to pronounce caffeine (audio) \

Medical Definition of caffeine

: a bitter alkaloid C8H10N4O2 found especially in coffee, tea, and kola nuts and used medicinally as a stimulant and diuretic

Other Words from caffeine

caffeinic \ ka-​ˈfē-​nik How to pronounce caffeinic (audio) , ˌkaf-​ē-​ˈin-​ik How to pronounce caffeinic (audio) \ adjective

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More from Merriam-Webster on caffeine

Rhyming Dictionary: Words that rhyme with caffeine

Spanish Central: Translation of caffeine

Nglish: Translation of caffeine for Spanish Speakers

Britannica English: Translation of caffeine for Arabic Speakers

Britannica.com: Encyclopedia article about caffeine

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