(idiomatic) bright, intelligent, sharp

head voice

(medicine) to craniotomize, to perform a craniotomy: to open the skull for surgery

(medicine) craniotomy: the opening of the skull for surgery

haughty

(idiomatic) to be sharp; to be keen; to be on the ball; to have a mind like a steel trap; to be clever

(idiomatic) to get mad; to be highly offended; to get pissed off; to get angry; to lose one's cool

(idiomatic) insane, crazy, nuts, out of one's mind

Alternative form of 頭がおかしい

(slang) a forgetful person