The act of a woman using the strength in her thighs to squeeze a man's head/neck, often in resulting in him being knocked out.
Men can do it to, but women's superior leg strength and the shape of the hips makes them far better at it.
Jake was so embarssed when he was play fighting with Lisa and she got her legs around his head. Her headscissor
was so tight he couldn't breathe and she made him beg for release.