To be entranced in a very extreme high brought on by drugs or a life long use of drugs. Also used by dousche bags to decribe their lives
Jesse: Bro my life is hella chill
Everyone else: shut up fag
This derives from a secret convention of both Nor and So Cal teenagers who decided to fuse the lingo of the state and thus formed "hella chill" meaning very cool or very good
Dude, trips to Mexico are hella chill. Y'all know what I'm saying!