Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “mental illness”

mental illness

noun [C or U]    
an illness that affects the mind
(Definition of mental illness noun from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)
Focus on the pronunciation of mental illness

Word of the Day

beneficiary

a person or group who receives money, advantages, etc. as a result of something else

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