The facial expression one makes to silently assert one's innocence under the scrutinous eye of an authority figure, typically involing squinted eyes and a large. toothy grin.
Not to be confused with the trollface.
Troll2: "Oh shit, it's the cops! Put on your coolface!"
CoolFace is the coolest name in the world. It started out as a replacement for the name "Cloud" in Final Fantasy 7 because the originator had thought that "Cloud" had "a cool face". From there, it has evolved to a name used by 1337 Starcraft players.
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.