off your head

off (one's) head

1. Crazy, insane, or eccentric. Often used humorously or sarcastically. I think you're off your head for changing careers this late in life, but, hey, follow your dreams. He's off his head if he thinks he can get that engine fixed by this weekend. My auntie likes to let people think she's off her head, but she's actually incredibly clever and witty.
2. Severely intoxicated by alcohol or drugs. No wonder he's failing—he's off his head damn near every night! We all popped the pills and were off our heads by the time the concert started.
See also: head, off

off your head

BRITISH, INFORMAL or

out of your head

INFORMAL
1. If someone is off their head or out of their head, they are crazy. You must be off your head to live in this area. If he didn't kill anybody it was only by luck because he was out of his head and screaming like a maniac.
2. If someone is off their head or out of their head, they have taken so many drugs or drunk so much alcohol that they do not know what they are doing. Basically, this song sounds great when you're off your head on Ecstasy. These days I get out of my head on one glass of wine.
See also: head, off

off (or out of) your head

1 mad or crazy. 2 extremely drunk or severely under the influence of illegal drugs. informal
See also: head, off

out of/off your ˈhead

(British English, informal)
1 crazy: Are you off your head?
2 not knowing what you are saying or doing because of the effects of alcohol or drugs: Don’t even try to have a proper conversation with him — he’s off his head.
See also: head, of, off, out
References in classic literature ?
If you don't sleep to-night," he said, "you'll be off your head to-morrow.
were so off your head on drugs that you allowed the sisters to spend whatever they liked and yes I believe every word the Grillos have said, who after all only stole money.
Around 200 bus rears will be adorned with a special strapline saying Drug Driving - You'd be off your head.
With a star-studded cast including Charles Dance, Sean Bean and Emilia Fox, you'd have to be off your head not to watch this.
It's very, like, romantic, and then, "I love you, you love me, and then you broke my heart, so my father's going to chop off your head.
He told Campbell: "He was clearly drunk and you were clearly off your head.
Another: ``To those of you who think you can vote and then run away, we will shadow you and catch you, and we will cut off your heads and the heads of your children.