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 of caffeine from the Web
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One way to prevent them is to drink caffeine, a natural stimulant that aids in alertness.
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It can be made with black tea, but many people prefer antioxidant-rich, low-caffeine green tea, Novak says.
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There are more than 30 e-sport tournaments and leagues, where caffeine is a bigger problem than steroids.
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Queeny’s coal-tar drug company, Monsanto, was also flush from lucrative contracts with Coca-Cola, who bought their caffeine, vanillin, and saccharin.
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Coffee lovers rejoice Get your caffeine fix, San Diego.
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Death Wish's regular coffee has 59 milligrams of caffeine per fluid ounce, or about 472 milligrams per cup.
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LaB Coffee and Roasters take their name to heart: the company serves their brew in beakers emblazoned with the chemical sign for caffeine.
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Roast type isn't related to strength or caffeine level, says Rubinstein.
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.
Origin and Etymology of caffeine
German Kaffein, from Kaffee coffee, from French café
Other Biochemistry Terms
CAFFEINE Defined for English Language Learners
Definition of caffeine for English Language Learners
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: a substance that is found especially in coffee and tea and that makes you feel more awake
CAFFEINE Defined for Kids
Definition of caffeine for Students
: a substance found especially in coffee and tea that makes a person feel more awake
Medical Dictionary
Learn More about caffeine
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See 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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