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
Leonhard	LE-awn-hahrt	German
Tijana	-	Serbian, Croatian
Anxo	AN-shaw	Galician
Karen (1)	KAH-ren (Danish), KER-ən (English), KAR-ən (English)	Danish, Norwegian, Icelandic, German, English
Lachie	-	Scottish
Pertti	PERT-tee	Finnish