(noun, adjective)


1. involving the mind or an intellectual process

- mental images of happy times

- mental calculations

- in a terrible mental state

Similar word(s): intellectual, noetic, rational, moral, psychic, psychical, psychogenic, psychological

2. of or relating to the mind

- mental powers

- mental development

- mental hygiene

3. of or relating to the chin- or liplike structure in insects and certain mollusks

4. of or relating to the chin or median part of the lower jaw

Similar word(s): genial

5. affected by a disorder of the mind

- a mental patient

- mental illness

Similar word(s): unhealthy

6. (colloquial) insane, mad, crazy.

Sentences with mental as an adjective:

- He is the most mental freshman I've seen yet.  He went mental on us.

- That was a mental party last night.

- the mental nerve;  the mental region


1. (zoology) A plate or scale covering the mentum or chin of a fish or reptile.