/koy"streuhl/ , n. Archaic.
a scoundrel; knave.
[ 1570-80; ME custrell, appar. coustillier, coustelier, one armed with a cou ( s ) telle dagger (fem. deriv. of coutel knife cultellus; see -IER 2 ), with -r- perh. from quystroun knave, page, scullion coistron coquistro ) ]