• balmy, barmy, batty, bonkers, buggy, cracked, cracker, crazed, crotchety, dorky, nutter, nutty, potty, psycho, queer, queer in the head, screwball, to be cracked, to be up the pole, touched, wacko, wacky, whacko, whacky, woody
• bin, booby hatch, crazyhouse, laughing academy, nuthouse
• lightheaded, queer, queer in the head, sicko
• bonkers, sicko, way-out, wayout
• to crack up, to flip, to freak out, to go blonkers, to go haywire, to go nuts, to go off one's head, to psych out
• off one's nut, to be out of one's head
• to be off one's rocker, to be off the rails
• she is a little peculiar