[laugh/scream/shout (etc.)] your head off

to laugh/scream/shout etc. very much and very loudly.

He laughed his head off when he read the letter.

• beat back
• beat back something
• be at beck and call
• beat brains out
• beat breast
• be at daggers drawn
• be at death's door
• beat down
• beat down on
• beat down on someone
• beat down on something
• be at each other's throats
• be at half-mast
• beat hands down
• be a thing of the past
• beat hollow
• be at home
• be a thorn in flesh
• be a thorn in side
• be a thorn in someone's flesh
• be a thorn in someone's side
• be a ... through and through
• Beat it!
• beat it
• be at it hammer and tongs