boef m (plural boeven, diminutive boefje n)
From Middle Dutch boef, boeve, bouve, from Old Dutch *buovo, from Proto-Germanic *bōbô, a reduplicated form of *bō- (“father, brother, male relative”).
Cognate with English bub, Pennsylvania Dutch Bub, German Bube, Icelandic bófi (“rogue, knave”). Related also to English babe, English boy.