Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English


English definition of “mental”


adjective [always before noun]     /ˈmentəl/
B2 relating to the mind , or involving the process of thinking : mental health / illness a mental disorder / hospital Science of psychology and psychoanalysisMind and personalityLogic and reason
mentally adverb B2 a mentally ill person
(Definition of mental adjective from the Cambridge Learner's Dictionary © Cambridge University Press)

Definitions of “mental” in other dictionaries

Word of the Day

best man

a male friend or relation of the bridegroom who stands with him and helps him during a marriage ceremony

Word of the Day


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