An Etymological Dictionary of the German Language/Bube
Bube, m., ‘box, lad, rogue, knave (at cards),’ from MidHG. buobe (MidLG. bóve), m., ‘boy, servant, disorderly person’ (OHG. *buobo and Goth. *bôba are wanting); a primit. Ger. word, undoubtedly of great antiquity, though unrecorded in the various OTeut. periods (yet note the proper names identical with it, OHG. Buobo, AS. Bôfa). Comp. MidDu. boeve, Du. boef (E. boy is probably based upon a diminutive *bôfig, *bôfing). ‘Young man, youth,’ is manifestly the orig. sense of the word; comp. Bav. bua, ‘lover,’ Swiss bua, ‘unmarried man.’ To this word MidE. babe, E. baby are related by gradation; also Swiss, bâbi, bœ̂bi (most frequently tokχebâbi, tittibâbi), ‘childish person’ (Zwingli — “Baben are effeminate, foolish youths”); akin to this is OHG. Babo, a proper name. The OTeut. words babo-bôbo are probably terms expressing endearment (comp. Ätti, Base, Muhme), since the same phonetic forms are also used similarly in other cases; comp. OSlov. baba, ‘grandmother’; further, Ital. babbéo, ‘ninny,’ Prov. babau, ‘fop’ (late Lat. baburrus, ‘foolish’), Ital. babbole, ‘childish tricks.’