If my boss heard me say that, he'd have laughed his head off.
"I thought they laughed it off a hundred years ago."
She had the sound way up and was laughing her head off.
I was sure that if she'd had any teeth she would have laughed them off.
I first read the book 10 years ago and laughed my head off.
I kind of smiled every once in a while and laughed it off.
I guess if anybody was looking, they'd have laughed their heads off.
I guess, as the rest of the team was laughing its head off.
I just laughed her off, and didn't make much secret of it, either.
Any other time I could have laughed my head off.