lmmffao Posted in L Best definition lmmffaointernet Laughing My Mother Fucking Ass Off. Another form of lmao and lmfao used exclusively on the internet. Bill: Well I told him ‘Your Mamma is so dumb she thinks sqaure roots are vegetables!’ Ted: LMMFAO How satisfied are you with the definition? Looking for lmmffao meaning? Delighted that you discovered the greatest determine on our web site! Recently this definition was actually observed 11 times.