roflmfao Share definition Flag an acronym used in online games or chatrooms combining the acronyms "rofl" and "lmfao". It usually means you are laughing harder than laughing your ass off. IrTEHn00b: How do I bring up teh start menu? Exampledude: ROFLMFAO! n00b! roflmfao by Sirius123 May 24, 2007 0 0 Get merch Get the roflmfao mug. Buy Now — $32.95 See more merch