caffeine

Rarely caf·fein

[ka-feen, kaf-een, kaf-ee-in]

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.

caffeine

/ 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

caffeine

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 .

Other Word Forms

• caffeinic adjective
• noncaffeine noun
• noncaffeinic adjective

Word History and Origins

Origin of caffeine¹

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

Word History and Origins

Origin of caffeine¹

C19: from German Kaffein, from Kaffee _coffee

Example Sentences

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.

Read more on BBC

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

Read more on 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.

Read more on Science Daily

Marcus added that "caffeine is also a diuretic, which could potentially reduce blood pressure and in turn lessen AFib risk. Several other ingredients in coffee also have anti-inflammatory properties that could have positive effects."

Read more on Science Daily

You can log daily symptoms, alongside mood, sleep quality and other factors such as caffeine, stress and supplements.

Read more on The Wall Street Journal

Related Words

• cappuccino 
• espresso