coistrel

[ koi-struh l ]
/ ˈkɔɪ strəl /

noun Archaic.

a scoundrel; knave.

Origin of coistrel

1570–80; Middle English custrell, apparently < Middle French coustillier, coustelier, one armed with a cou(s)telle dagger (feminine derivative of coutel knife < Latin cultellus; see -ier2), with -r- perhaps from quystroun knave, page, scullion < Anglo-French (Old French coistron < Vulgar Latin *coquistrō)