An Etymological Dictionary of the German Language/Nichte
Nichte, f., ‘niece,’ ModHG. only (unknown to UpG. dialects in which Base is used), from LG. nicht, in MidHG. niftel, OHG. niftila, f. (dimin. of OHG. nift); comp. AS. nift, OIc. nipt. These are fem. forms of Neffe, pointing to Goth. *nifti, pre-Teut. neptî, f., from nepôt, m. The meaning of Nichte fluctuates as in the case of Neffe; MidHG. niftel, ‘niece, mother's sister, first cousin,’ OIc. nipt, ‘sister’s daughter, niece,’ OHG. nift, ‘neptis privigna.’ Comp. also Lat. neptis, ‘granddaughter,’ with nepos; Sans. naptî, f., ‘daughter, granddaughter,’ with nâpât.