caffeine

American  

[ka-feen, kaf-een, kaf-ee-in] / kæˈfin, ˈkæf in, ˈkæf i ɪn /

Rarely caffein

noun

1. Chemistry, Pharmacology. a white, crystalline, bitter alkaloid, C 8 H 10 N 4 O 2 , usually derived from coffee or tea: used in medicine chiefly as a nervous system stimulant.

2. Informal. a drink, usually coffee or tea, containing this stimulant.

   We sipped our caffeine on the balcony with its views of sea stacks, rocky coves, and the ever-changing ocean.

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caffeine British  

/ ˈkæfiːn, ˈkæfɪˌiːn /

noun

1. a white crystalline bitter alkaloid responsible for the stimulant action of tea, coffee, and cocoa: a constituent of many tonics and analgesics. Formula: C 8 H 10 N 4 O 2 See also xanthine

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caffeine Scientific  

/ kă-fēn′ /

1. A bitter white alkaloid found in tea leaves, coffee beans, and various other plant parts. It is a mild stimulant. Caffeine is a xanthine and similar in structure to theobromine and theophylline. Chemical formula: C ₈ H ₁₀ N ₄ O ₂ .

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Other Word Forms

• caffeinic adjective
• noncaffeine noun
• noncaffeinic adjective

Etymology

Origin of caffeine

First recorded in 1820–30; from French caféine, equivalent to café coffee + -ine -ine ²

Compare meaning

How does caffeine compare to similar and commonly confused words? Explore the most common comparisons:

• theobromine vs. caffeine

Example Sentences

They also note that they lacked details about several potentially important factors such as the type of coffee consumed, when it was consumed, the exact caffeine content, and whether participants drank other caffeinated beverages.

From Science Daily

During the test, for example, if a user saw a sponsored prompt that said, “What energy drink has the most caffeine?” and clicked on it, Sparky responded.

From The Wall Street Journal

Coffees made with extra ingredients like mushrooms, protein and collagen are known as "functional coffees" - which aim to provide consumers with benefits beyond the typical caffeine boost.

From BBC

“By two o’clock in the afternoon, they put me in a conference room,” says Matthews of her subsequent caffeine crash.

From The Wall Street Journal

To improve sleep quality, consistent bedtimes, limiting screen use before sleep, reducing caffeine and alcohol, and maintaining a quiet, cool environment are all advised.

From Science Daily

Related Words

• cappuccino
• espresso