To destroy or abolish something.
To obscure or eclipse something.
To hunt down (a species) to extinction.
To bring about the extinction of a conditioned reflex.
To put out, as in fire; to end burning; to quench.
To die out.
To kill.
To reject something.
No.
Nothing; nix; often in the phrase "ixnay on ...", indicating something that must not be mentioned, often in Pig Latin