An inaccurate variant spelling of "lolocaust," circulated particularly among the semi-literate and those who clearly haven't read much about the Second World War.
That someone took the time to submit a separate entry on 'lolocost' when the more obvious definition is just above it in the Urban Dictionary—it's enough to precipitate the lolocalypse.
One who casts forth lulz;
instrument of/or guitarist who fails so epically that one cannot help but laugh. (combination of lol and -caster, suffix to many Fender guitars)
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?"