Nix is most commonly used as a verb. Close synonyms of this sense are veto, deny, reject, and refuse. Nix is usually a bit more informal than these.

This sense of nix is used in the context of saying no to or rejecting ideas, plans, suggestions, proposals, etc. When someone is said to have nixed something, it typically means that they have given it a hard no. In other words, when something is nixed, it’s often denied or rejected permanently.

You could also use words like quash or cancel.

Relatedly, nix can be used as a noun meaning a rejection or a refusal. This is kind of like saying that something has gotten the ax. 

Nix can be used as a noun meaning “nothing,” as in zero, zip, zilch, nada, nil, naught.

It can also mean no, but this isn’t commonly used.

Sometimes, nix is used as an interjection of warning, similar to Watch out! or Be careful!

The word nix comes from a variant of the German word nichts, which means “nothing.” The first records of the word in English come from the late 1700s.

Nix is a pretty informal word that’s often used in casual communication. It’s sometimes used in news headlines as a shorter way of saying reject.

Here are some examples of nix in a sentence:

• My mom nixed my plans of staying up late to watch a horror movie.
• The board nixed the policy proposal without even taking any comments on it. 
• At first, we were going to paint it, but we decided to nix that idea.