Definition of caffeine Caffeine

/kæfiˈn/ - [kafeen] - caf•feine

We found 7 definitions of caffeine from 7 different sources.

What does caffeine mean?

WordNet

Noun Plural: caffeines
caffeine - a bitter alkaloid found in coffee and tea that is responsible for their stimulating effects
		caffein
		alkaloid natural bases containing nitrogen found in plants
		java, coffee a platform-independent object-oriented programming language
		tea a light midafternoon meal of tea and sandwiches or cakes; "an Englishman would interrupt a war to have his afternoon tea"

= synonym
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Wiktionary

caffeine (Noun)
An alkaloid, C8H10N4O2, found naturally in tea and coffee plants which acts as a mild stimulant of the central nervous system.

Webster DictionaryWebster's Unabridged Dictionary 📘

caffeine (n.)
A white, bitter, crystallizable substance, obtained from coffee. It is identical with the alkaloid theine from tea leaves, and with guaranine from guarana.

OmegaWiki DictionaryOmegaWiki Dictionary Ω

caffeine
An alkaloid, C8H10N4O2, found naturally in tea and coffee plants which acts as a mild stimulant of the central nervous system.

Chambers DictionaryChamber's 20th Century Dictionary 📕

caffeine
kaf′e-in, or kaf-ē′in, n. the alkaloid or active principle of coffee and tea. [Fr. caféine. See Coffee.]

Wikipedia

Caffeine is a drug (or chemical) that is found in plants. In large amounts it can kill humans and other animals. Even small amounts can kill some animals, such as dogs.

Where caffeine is from.

Caffeine is the main drug that is in coffee. Coffee comes from a tree. The seeds of the tree are roasted to make coffee.

Caffeine comes from other plants as well. It is found in guarana, yerba maté, cacao, and some plants used to make tea. The plants use caffeine as a "pesticide". This is a chemical that kills insects if they eat the plant. It is the way the plant protects itself.

It is called guaranine when it comes from the guarana plant and theine when it comes from a tea plant. It is called mateine in the mate drink. This drink is an infusion made with Yerba mate.

What caffeine is.

Caffeine is a "stimulant" drug. A stimulant is a drug that increases body actions like heart rate, blood pressure, and metabolism. It makes a person feel more awake and alert.

Caffeine also is a diuretic. This means it makes a person make more urine (the waste liquid a person makes).

The caffeine chemical is called a "xanthine alkaloid". This is a group of chemicals that are stimulants. Some xanthine alkaloids (like theophylline) are used to help asthma.

What caffeine is used for.

The biggest use of caffeine is as a stimulant. People drink coffee and other drinks with caffeine to stay awake.

Doctors sometimes use caffeine as a medicine. It is used for headaches (head pain). It is sometimes used to help pr