Webster's Revised Unabridged Dictionary · 1913

Mental

Mental , adjective

[Latin mentum the chin.]

(Anatomy) Of or pertaining to the chin; genian; as, the mental nerve; the mental region.

Mental , noun

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

Mental , adjective

[French, from Latin mentalis, from mens, mentis, the mind; akin to English mind. See Mind.]

Of or pertaining to the mind; intellectual; as, mental faculties; mental operations, conditions, or exercise.
What a mental power This eye shoots forth! — Shakespeare
Collocations (2)
Mental alienation , insanity.
Mental arithmetic , the art or practice of solving arithmetical problems by mental processes, unassisted by written figures.