After a few reloads it produced "clampless". Seemed to have a pretty well defined meaning and googling it suggests many people use it in the obvious way.

The generated definition was a bit odd though:

> without a hard surface or padded pad of material "a clampless mattress"

EDIT: just noticed you can add a link, so here it is: https://l.thisworddoesnotexist.com/29Fj