An Etymological Dictionary of the German Language/Dieb
Dieb, m., ‘thief,’ from the equiv. MidHG. diep(b), OHG. diob, m.; common to the Teut. group; comp. Goth. þiufs(b), Du. dief, AS. þeóf, E. thief. The word cannot be traced beyond Teut. In the sense of ‘Diebstahl,’ E. has a form with a dental suffix — AS. þŷfþ, f. (OIc. þýfð, s., Goth. *þiubiþa), E. theft. The form in HG. is a j- stem — OHG. diuba (diuva), MidHG. diube (diuve), earlier ModHG. Deube (as late as Logau, 1604-1655), which is now met with only in Wilddeube, ‘petty poaching.’ The latter forms the base of ModHG. Diebstahl, in MidHG. diepstâle and diupstâle (OSwed. þiufstolet), lit. ‘theft-stealing.’ The second part of the compound expresses the same idea as the first; Dieb is simply the concrete which has replaced the abstract; comp. Goth. þiubi, n., and its adv. form þiubjô, ‘secretly.’ Besides the masc. Dieb, there existed in OHG. and MidHG. a feminine form, which in Goth. would have been *þiubi; comp. OHG. diupa, MidHG. diupe, ‘female thief.’ We must seek for the primit. word in a pre-Teut. root with a final p; this is proved by OHG. diuva, MidHG. diuve, f., ‘theft’; comp. the Aryan root tup, ‘to duck,’ under Ducht.