be off (one's) nut

slang To be crazy and/or wacky. Usually used humorously. Don't listen to a word he says, he's off his nut! You're off your nut if you think that plan will work.

Common Names:

Name	Pronounced	Usage
MiklÓS	MEEK-losh	Hungarian
Marcela	mahr-THE-lah (Spanish), mahr-SE-lah (Latin American Spanish), mahr-TSE-lah (Polish), mahr-CHE-lah (Romanian), MAHR-tse-lah (Czech)	Spanish, Polish, Romanian, Czech
Matvei	maht-VYAY	Russian
Astor	['æstə]
Vangel	-	Macedonian
Stevie	['sti:vi]