A very versatile word - it can be used to express inundating joy, acceptance, willingness, indifference, sarcasm and pretty much any emotion/expression capable to man. It can also be used to piss your friend the fuck off.
Must be said in a CAPS LOCK manner with a sort of Quagmire type inflection, and a bit of fob..... ALRAIT.
Boris: "Dude, let's knock up some cherry pies!"
Boris: "and then maybe we can go skinny dipping"
Gianni: " ALRAIT"
Boris: "...uh... dude, did you just piss on my leg?"
Gianni: " ALRAAAAAAIIIITT"
Boris: "...fuck you dude."
Gianni: ".......... ALRAIT"