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 Consumers are looking for waters that are alkaline or that contain antioxidants or caffeine, and brands are exploring different functional claims as a way to stand out. Laura Reiley, Washington Post, "As soda sales stagnate, Coca-Cola turns to the vivacious sparkling water market for new fizz," 7 Nov. 2019 In terms of flavor profile, the robusta variety boasts nearly two times the caffeine content of its counterpart and gives off a nutty, full, dark, chocolaty taste. Fortune, "The First U.S. Importer, Roaster, and Distributor of Vietnamese Coffee Talks of Shifting Industry," 29 Sep. 2019 The same lifestyle factors that can affect your skin overall can damage the moisture barrier: Not drinking enough water or drinking too much alcohol or caffeine. Leah Prinzivalli, Allure, "The Complete Guide to Your Skin's Moisture Barrier and How to Protect It," 22 Sep. 2019 Seals’ tips for controlling stress during the interview are: Avoid caffeine (coffee, tea, chocolate) prior to the interview. Bob Weinstein, Houston Chronicle, "It’s important to manage job-interview stress," 21 Sep. 2019 These places are filling stations for the body, where tired drivers can replenish with water, caffeine, taurine, and nicotine or indulge in sugar or salt without judgment, because diets don’t apply here. Tony Rehagen,, "Farewell to hot dog rollers and roadside chats: an elegy for the American gas station," 11 July 2019 The cream’s caffeine content and cooling tip deflates puffy eyes, and its slight tint masks dark circles without looking like an actual mask. Ashley Weatherford, The Cut, "Your Allergy Season Survival Guide," 11 Apr. 2018 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

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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Learn More about caffeine

Time Traveler for caffeine

Time Traveler

The first known use of caffeine was circa 1823

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Statistics for caffeine

Last Updated

2 Dec 2019

Cite this Entry

“Caffeine.” The Dictionary, Merriam-Webster Inc., Accessed 5 December 2019.

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More Definitions for caffeine


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


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


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 Encyclopedia article about caffeine

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