LMAO

UK
/ɛl ɛm eɪ ˈəʊ/
US
/ɛl ɛm eɪ ˈoʊ/
LMAOinterjection
UK
/ɛl ɛm eɪ ˈəʊ/
US
/ɛl ɛm eɪ ˈoʊ/
Internet slang acronym; used as an exclamation expressing strong amusement or laughter.
Definitions
An exclamation used in online communication to indicate that something is very funny or that one is laughing very hard.
LMAO, that was the funniest thing I've seen today.