lmso Share definition Flag laughing my socks offused by those who aren't allowed to say ass Kelly: Did you see the show last night? Tyler: Yeah, it was so funny. Rosie: I know! It was sooo lmso! lmso by ROFLWPL January 31, 2010 0 0 Get merch Get the lmso mug. Buy Now — $32.95 See more merch