an acronym for "rolling on floor laughing my ass off". it is mostly used in electric communications sucha as IM, texts and emails, to describe the state when you are laughing to the extreme. it is greater than lol or rofl.
dan: julie & i we were totally roflmao at the office!
wife: heh..yeah. *continues reading*
dan to julie online: well, i've told her. she didn't care. let's roflmao again tomorrow.