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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In addition, drinking more fluids, including soup, caffeine-free teas and water can help.
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Need that post-lunch caffeine and sugar pick-me-up?
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Infused with caffeine, this azure-blue gel stick glides over skin seamlessly, chilling it along the way.
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And when all causes of death were combined, even slow caffeine metabolizers had a longevity boost.
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And when all causes of death were combined, even slow caffeine metabolizers had a longevity boost.
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Of course caffeine dries out your skin, gives you headaches, and causes you immense guilt for choosing cold brew over cold water.
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And when all causes of death were combined, even slow caffeine metabolizers had a longevity boost.
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And when all causes of death were combined, even slow caffeine metabolizers had a longevity boost.
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
NEW! Time Traveler
First Known Use: circa 1823
in the meaning defined above
See Words from the same yearOther 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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