look up any word, like the eiffel tower:
 
1.
Either someone who makes you laugh, someone who is the bomb, or if used sarcasicly,a massive tool usually on xbox live.
1. Tim: Did you hear Toms dirty joke?

Pat: Yeah, what a roflbacker.
2. Jim: 15 killstreak!

Hornito: Dude you are a roflbacker.
3. (Jhonny get spawn killed) Wow you would spawn kill me, what a roflbacker