1) To be in a relaxed state, calm and not in the mood to shank the person next to you for saying they like your package, and they are clearly a guy.
2) To think something is cool.
1) Franklin:*takes a seat next to Bill*
Bill: *checks out Franklin* "Hey man, I think you got a hot package"
Franklin: *stands in a form of anger, and prepares to shank Bill, then realizes that he is chill, and takes a seat* "Thanks man. ^-o"
2) "Hey Willis, did you know that your name is so Chill!"