Derived from the world of chan, nou is the universal comeback to any statement when one has no intelligent comeback, or simply wants to be an arrogant asshole. It as an acronym for No you, or no u.
Unlike the famous "lol" or "omg" this word has a very poor chance of being remembered as an internet acronym, so stop using it. Gaia fagggots.
Now more commonly typed as "nou", rather than "no you" or "no u".
Using this word in an argument may cause your friends to think you as simple minded/retarded/a dick.
1: fishluv24: Why are you and Rachael going out? She's ugly as fuck, dude!
datwunguiolol: nou (No, you)
2: Phone: Jeremy? Hey, I need you to go pick up supper for me. It's getting late and your sister is probably hungry.
Teen: nou (No, you)