Nix
late 18th century (as a noun): from German, colloquial variant of nichts ‘nothing’.
wiktionary
From German nix, colloquial form of nichts(“nothing”). [1] [2] Compare also Dutch niks(“nothing”), informal for niets(“nothing”). More at naught.
From German Nix, from Middle High German nickes, niches, from Old High German nichus, nihhus, from Proto-Germanic *nikwus(“water-spirit; nix”), from Proto-Indo-European *neygʷ-(“to wash”). Cognate with Old English nicor(“a water-monster; hippopotamus”).
etymonline
nix (n., interj.)
as an answer, "nothing, none," 1789, from German nix, dialectal variant of nichts "nothing," from Middle High German nihtes, from genitive of niht, nit "nothing," from Old High German niwiht, from ni, ne "no" (from PIE root *ne- "not") + wiht "thing, creature" (compare naught). By extension, as an adverb, "no."
nix (v.)
"cancel, refuse, forbid," 1903, from nix (n.). Related: Nixed; nixing.