MENTAL

adj. 1 intellectual, cognitive, cerebral, perceptual, rational, conceptual, theoretical, noetic, abstract The boy staggered us with his ability to perform rapid mental arithmetical calculations 2 lunatic, mad, crazy, psychotic, demented, mentally ill, unstable, unbalanced, deranged, disturbed, daft, certifiable, Slang off one's rocker, nutty, batty, balmy or barmy, loony, screwy, bonkers, crackers, nuts, bananas, loco My great-aunt has gone a bit mental in her old age