Y. Laa
What you say after doing, or watching someone do, something stupid/lame.
"Y. Laa" = "You Lame Ass"
"Y. Laa" = "You Lame Ass"
You and a group of friends witness someone doing something stupid and you all shout, "Y. Laaa!!!" at him but he doesn't know what it means or know if you are shouting at him or not. (Lots of fun.)