An abbreviation which takes online chatabbreviations entirely too far. First "lol" was used to relay laughter, then it was promoted to "rofl" or "lmao" to emphasize something being more than just funny. Then some chatroom junkies combined the latter 2 to create "roflmao" to emphasize an even higher level of laughter. Sometimes things are so utterly hilarious that "roflmao" doesn't quiten the degree of humor, so another "f" has to be added.
Abbrevation for; "Rolling on floor, laughing my fucking ass off" and somtimes used "Rolling on floor, laughing my fat ass off." It is a mixture of "Rofl" which is "Rolling on floor laughing" and "lmfao" "laughing my fucking/fat ass off."