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

Examples of caffeine in a Sentence

Her doctor told her to avoid caffeine.
Recent Examples on the Web Besides Vibratin’ Katie, there’s Alicia the professional ballerina, Abigail who was born deaf, Kristin who is a lawyer who loves a rooftop bar, Magi the pharmacist from Ethiopia, Anna who is a caffeine fiend, and Sarah the reporter. Ali Barthwell, Vulture, "The Bachelor Season Premiere Recap: Just Vibing," 5 Jan. 2021 The latest wave of masks contain a host of de-puffing, fine-line-plumping actives, from caffeine and rejuvenating rose quartz to 24-karat gold. Zoe Ruffner, Vogue, "19 Under-Eye Patches to Banish Puffiness Once and for All," 23 Dec. 2020 The two-in-one formula is a cross between a serum and balm and includes firming caffeine. Maya Mcdowell, Marie Claire, "A Beauty Editor's Guide to Winter Skincare," 28 Dec. 2020 Coffee lovers may be able to get their dose of caffeine at Starbucks but not all stores will be open or following their regular schedules. Leada Gore |, al, "Christmas Day 2020: What’s open, what’s closed on Dec. 25? Starbucks, Walmart, stores, more," 25 Dec. 2020 Not to mention, any would make a great gift for the caffeine fiend in your life. Chelsea Stone, CNN Underscored, "The best sales to shop today: Marmot, Ninja, Samsung and more," 15 Dec. 2020 For the caffeine enthusiast in your life, pick up a bag of the local panadería’s bestselling beverage to prepare at home: a ready-to-brew blend of organic Oaxacan coffee beans, Mexican cinnamon and brown cane sugar. Los Angeles Times, "The food gift guide that also supports L.A. restaurants and businesses," 30 Oct. 2020 For those looking to liven up their coffee intake and bust out of the caffeine doldrums, here are seven different types of coffee drinks and where to find them around Dallas. Claire Ballor, Dallas News, "7 Dallas coffee drinks that will switch up your caffeine routine," 20 Oct. 2020 This provides all the needed caffeine to motivate the Buffaloes: A chance to remain among the undefeated. Mark Heim |, al, "No. 21 Colorado-Utah live stream (12/10): How to watch college football online, TV, time," 12 Dec. 2020

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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Time Traveler for caffeine

Time Traveler

The first known use of caffeine was circa 1823

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Statistics for caffeine

Last Updated

18 Jan 2021

Cite this Entry

“Caffeine.” Dictionary, Merriam-Webster, Accessed 19 Jan. 2021.

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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 caffeine (audio) , ˌkaf-​ē-​ˈin-​ik How to pronounce caffeine (audio) \ adjective

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More from Merriam-Webster on caffeine

Nglish: Translation of caffeine for Spanish Speakers

Britannica English: Translation of caffeine for Arabic Speakers Encyclopedia article about caffeine

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