"Rassclat" is a derivative of "Bumpaclat" and "Pussyclat", both of which are Jamaican slang for menstral sanitary towels (Tampons and Pads). "Rassclat" can sometimes be shortened to "Rass".
"Rassclat" can be used as an adjective to disparage an object, but it is most often used as a highly offensiveinsult against a person.
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.
FRIEND A: "Did you just take a stealthie of me?"
FRIEND B (turning phone around): "no I was just using snapchat's new filter, see?"