An Etymological Dictionary of the German Language/doch
doch, conj., ‘yet, however,’ from MidHG. doch, OHG. dŏh, ‘yet,’ also ‘although’; ŏ, on account of the toneless nature of the conj., is shortened from ô; Goth. þáuh, corresponding to AS. þeáh, E. though. Scarcely from þa (variant of þata, HG. daȥ) and uh, ‘and.’ Goth. þauh is lit. ‘and that’?.