The definition of the word creasage is when you find something really funny that makes you laugh your head off. Also another word for creasage is lolage or lol.
The "proper" term for Butt Cleavage, made accessible to booty watchers everywhere by ultra low rise jeans and pants. While sometimes seen with a whale tale, au naturale is the preferred display. This is the also discreet way to refer to it when seen in the wild.
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.