Rofl means rolling on floor laughing.
Hence the R.O.F.L
But just like every other word from the internetz it has evolved in many ways such as roflmao meaning rolling on floor laughing my ass off. It has also seemed to evolve to food products such as rofl my waffle or rofl my brothel sprouts.
Jim: I had sex with a male donkey.
Delores: Rofl why?
Jim: Because sex with male donkeys are good luck
Prices shown in USD.