The bastardization of "seriuosly", even though I don't get why they just can't type out the whole damn word. God. It takes like .5 more of a second. It's usually used by "scene" kids, in order for them to sound even stupider then they already do.
Kid 1: Yesterday I found an old hairy man in my backyard. He bought me a flower.
Kid 2: srsly?
Kid 1: No. Go away.