To be, or being synonymous with, a wanker. Someone who's unbounding perspicacity is slightly let down by the fact that they're a tosser. A person who's vaunted powers of ratiocination are eclipsed by their general pusillanimous and rodomontade manner. Also a human who can be affiliated with near relatives who happen to be troglodytes.
Dave: Gary has been so snibberish since he joined the Glee club.
Phil: Yes, what a fuckup.
Gary: Hello lads, fancy a game of chess?
Dave and Phil: Fuck off Gary
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?"