caffeine

noun

caf·​feine ka-ˈfēn How to pronounce caffeine (audio)
ˈka-ˌfēn
: 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 Their Japanese Cold Brew Coffee is the perfect beverage to accompany their scratch made foods and provides just the right caffeine buzz to start off the day. Felicia Campbell, The Arizona Republic, 12 Mar. 2024 Some people love their caffeine and will drink their coffee at the predawn meal, suhoor. Jocelyn Solis-Moreira, CNN, 10 Mar. 2024 Friday has a coffee deal for anyone who needs a caffeine boost. Sabrina Weiss, Peoplemag, 5 Mar. 2024 The 30-ounce size is packed with 192 milligrams of caffeine (equivalent to nearly four espresso shots) and 37 grams of sugar (two grams less than a can of Coke). Li Goldstein, Bon Appétit, 23 Feb. 2024 And to support my daily caffeine addiction on those trips, that usually meant bringing along instant coffee and a pot to boil water over an open fire – for the sake of convenience. Scott Kramer, Forbes, 18 Feb. 2024 List caffeine eye cream which also contains the winning combo of caffeine and Matrixyl 3000 to help depuff and reduce the appearance of wrinkles over time. Macaela MacKenzie, Glamour, 17 Feb. 2024 The oil-free formula is packed with ingredients like squalane and glycerin for moisture, and caffeine to brighten the skin, decrease puffiness, and soothe inflammation. Danielle Cohen, Glamour, 1 Mar. 2024 The limit actually does exist: Most adults should have no more than 400 milligrams of caffeine per day, according to the FDA. Li Goldstein, Bon Appétit, 23 Feb. 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.

Word History

Etymology

German Kaffein, from Kaffee coffee, from French café

First Known Use

circa 1823, in the meaning defined above

Time Traveler
The first known use of caffeine was circa 1823

Dictionary Entries Near caffeine

Cite this Entry

“Caffeine.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/caffeine. Accessed 29 Mar. 2024.

Kids Definition

caffeine

noun
caf·​feine ka-ˈfēn How to pronounce caffeine (audio)
ˈka-ˌfēn
: a bitter stimulating compound found especially in coffee, tea, cacao, and kola nuts

Medical Definition

caffeine

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

More from Merriam-Webster on caffeine

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