(niks) noun
In Teutonic mythology, a water spirit appearing in male or female form, and sometimes appearing as part fish. [<G nix]
—nix′ie noun fem.

(niks) Slang noun
1. Nothing.
2. No.
—adverb No.
—interj. Stop! Watch out!: an exclamation urging someone to stop saying or doing something.
—v.t. To forbid or disagree with: He nixed our suggestions on the matter. [<G nichts nothing]