adjective

1. of or for the mind or intellect mental powers, mental aids
2. done by, or carried on in, the mind (i.e., without using written symbols) mental arithmetic
3. 1. of, having, or related to mental illness or any psychiatric disorder a mental patient, mental health
   2. Informal mentally deranged; insane
4. for the mentally ill a mental hospital
5. having to do with mind reading, telepathy, etc.

Etymology: ME < MFr < LL mentalis < L mens (gen. mentis), mind

adjective

Etymology: < L mentum, the chin < IE base *men-, to project + -al