An Etymological Dictionary of the German Language/Annotated/Bube
Bube, masculine, ‘box, lad, rogue, knave (at cards),’ from Middle High German buobe (Middle Low German bóve), masculine, ‘boy, servant, disorderly person’ (Old High German *buobo and Gothic *bôba are wanting); a primitive German word, undoubtedly of great antiquity, though unrecorded in the various Old Teutonic periods (yet note the proper names identical with it, Old High German Buobo, Anglo-Saxon Bôfa). Compare Middle Dutch boeve, Dutch boef (English boy is probably based upon a diminutive *bôfig, *bôfing). ‘Young man, youth,’ is manifestly the original sense of the word; compare Bavarian bua, ‘lover,’ Swiss bua, ‘unmarried man.’ To this word Middle English babe, English 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 Old High German Babo, a proper name. The Old Teutonic words babo-bôbo are probably terms expressing endearment (compare Ätti, Base, Muhme), since the same phonetic forms are also used similarly in other cases; compare Old Slovenian baba, ‘grandmother’; further, Italian babbéo, ‘ninny,’ Provençal babau, ‘fop’ (late Latin baburrus, ‘foolish’), Italian babbole, ‘childish tricks.’