Seems that no one knows how this originated so let me break it down. It first appeared on the saturday morning cartoon Batman, where Batman approaches Freeze and Mr. Freeze says im chillin like a villan, hence why he was chillin (literal definition).
Batman: Freeze what are you doing?
Mr. Freeze: chillin like a villan
Trent, 'spelt' is British English for 'spelled'.
Anyway, as said before, it's SPELT "chillin like a villAIN" not "chillin like a villian". It means you are really relaxed et cetera. like a head of a rich criminal organization
"What are you doing?"
"Chillin' like a villain"
no one really knows what it means... but it rhymes.
Drew: Hey buddy wussup?
Alec: Nothin much, just chillin' like a villian