Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “serotonin”

serotonin

noun [U] uk   /ˌse.rəˈtəʊ.nɪn/ us    /-ˈtoʊ-/
a neurotransmitter (= a chemical in the body that carries messages from the brain) that helps you feel relaxed and happyAnimal biochemistry
(Definition of serotonin from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
What is the pronunciation of serotonin?
Add Cambridge dictionaries to your browser to your website

Definitions of “serotonin” in other dictionaries

Word of the Day

hoppy

like hops (= dried fruit used to make beer)

Word of the Day

Blog

Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More