your head off

(one's) head off

Very intensely or loudly; with no restraint, hesitation, or inhibition. (Used after verbs associated with speech sounds, such as "yell," talk," "laugh," etc.) I'm telling you, Mark's boyfriend is hilarious! He had me laughing my head off when I met him. Suzy started yelling her head off when I told her she couldn't have an ice cream cone. A: "So, has Noah started saying any words yet?" B: "And then some—he's been talking his head off for months now!"
See also: head, off
Farlex Dictionary of Idioms.

— your head off

laugh, talk, shout, etc. with a complete lack of restraint or without stopping.
1990 Paul Auster The Music of Chance Now that the kid was out of danger, he began to show his true colors, and it wasn't long before he was talking his head off.
See also: head, off
Farlex Partner Idioms Dictionary
See also:
  • (one's) head off
  • head off
  • be laughing (one's) head off
  • be laughing your head off
  • laughing in the aisles
  • laugh head off
  • laugh your head off
  • laugh (one's) head off
  • laugh away
  • make as though
References in classic literature
"You must excuse me for taking your head off, but I shall have to do it in order to put your brains in their proper place."
The Wonderful Wizard of Oz
Might as well be dead an' done with it as work your head off that way.
The Valley of the Moon
He walks the poop darting gloomy glances, as though he wished to poison the sea, and snaps your head off savagely whenever you happen to blunder within earshot.
Mirror of the Sea
Taylor's defence solicitor, Andrew Gibb, said: "You were rocking back and fore in the chair and were banging your head off the wall." But the child replied: "No."
TEACHER 'HIT KID AGAINST WALL'
During an ejection or other mishap, "if the (system) is improperly connected, it could rip your head off."
Air force print news (Oct. 13, 2004): helmet upgrades enhance air power
At Cardiff Magistrates' Court, prosecutor Mike Evans said: 'Mr Tapps said to the traffic warden 'You put that on the car and I'll take your head off.'
IRATE DRIVER THREATENED CITY WARDEN
'Moremon ran up the stairs shouting, 'You had better get out of here or I'll blow your head off'.'
Father's threat to shoot feud son