Haxor is slang for hacker. As with all slang, hax0r can be used for many purposes.
1) Used as a term of appreciation
2) Humour, insult
3) To reveal the truth that you are a real newb
4) As a war call or to cheer another on.
1) Thanks for hax0ring that three hundred dollar aluminum case so that Zalman fan would fit. I'm glad you have such a handy bag of haxor tools. I know I don't have an eighteen inch set of metal cutters.
2) That newb is l33t h@x0r.
3) i r l33t h@x0r! All that neon light adds at least 15MHz to the system. Serious! Mitnick told me it does on IRC.
4) Haxor! Haxor! Haxor!
An oval Korean cake. As known as 'Honey Costella'.
Oh man, I got fob cake for lunch again.