LMFAOSHTIHAHAAD Share definition Flag The acronym for: LAUGH MY FUCKING ASS OFF SO HARD THAT I HAD A HEART ATTACK AND DIED Jonathan that shit you did last night made me LMFAOSHTIHAHAAD. LMFAOSHTIHAHAAD by Anti-Boo August 14, 2012 Get the LMFAOSHTIHAHAAD mug.