An Etymological Dictionary of the German Language/Annotated/noch

noch (1.), adverb, from the equivalent Middle High German nock, Old High German noh, ‘still’; corresponding to Old Saxon noh, Dutch nog, Gothic nauk, ‘still’; a compound of nu, ‘now,’ and h, equivalent to Latin que, Greek τε, Sanscrit ca, ‘and also’; therefore the originally meaning is probably ‘also now,’ or ‘even, just now’; compare nun, and with regard to Gothic h-, equivalent to Latin que, see noch (2).

noch (2.), conjunction, ‘nor,’ from Middle High German noch, Old High German noh, ‘nor, not even, and not even’; Old High German nohnok, Middle High German noch-, noch, ‘neither—nor,’ also even in Middle High German wëder—noch. Corresponding to Old Saxon noh, Dutch noch; in Gothic nih, ‘nor, not even,’ Gothic nih—nih, ‘neither—nor.’ Gothic nih is exactly equivalent to Latin ne-que (with regard to Gothic ni, Latin ne, see nicht). The particle -h, -uh, corresponding to Latin que, Greek τε, Sanscrit ca, ‘and,’ had a definite meaning in Gothic.