51u3d Share definition Flag a term invented by an unknown "l33t h4xx0r" who most likely was a 12 year old AOLing faggot. just flip it. youll understand its immaturity and stupidty then. that n00b h45 a t1ny 51u3d lol!!!111 51u3d by Hybrid March 11, 2005 0 0 Get merch