English

loosejaw

From loose + jaw.

A compound of loose + jaw

Proto-Indo-European *lewh₁- ‘to cut, untie, loosen’

…

Proto-Germanic *leusaną ‘to lose’

Proto-Germanic *lausaz ‘loose’

Old Norse lauss ‘loose, free’

Middle English loos ‘loose, free’

English loose

Middle English jawe/jowe

English jaw

Today it means

noun A fish whose jaw can unhinge to swallow large prey.

Language periods are conventional ranges, not dates for this word.

Etymograph / loosejaw