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

Alternative form of 頭がおかしい

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

iridescent; having different colours when the angle of view or illumination changes / ambiguous or vague; using weasel words

(slang) a forgetful person

(Shinto) the part of the soul that's gentle, as opposed to the violent 荒御魂 (aramitama)

(idiomatic) to come into mind, to pop into one's head

(idiomatic) to keep in mind

"to enter the head": for learning to stay in one's head

eyeball