An abbreviation which takes online chat abbreviations 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.
Dumbass: "d00d ZOMG liek I like totally r4nk3d y0 azz j00 n00b!! ROFLMFAO"