Introduced by the character Tobias Funke (David Cross) on the short-lived but acclaimed, award winning FOX sitcom Arrested Development. "Douche chill" is an exclamation calling attention to the embarrassment of someone who has brought ill consequences on themselves.
Typically annunciated an octave or two higher than one's normal speaking voice and drawing out the "L" sound in "chill."
1. Mike and Tom are playing one-on-one basketball. Mike tries to show off and go up for a dunk. He misses it and face plants on the concrete. The sooner the better, Mike exclaims, "Douche chilllllll!"