It is an internet slang and an acronym which stands for In My Arrogant Opinion. It is the new age take on the old cliche - in my humble opinion or IMHO. Another variation of IMAO is IMNSHO (In My Not-So-Humble Opinion)
when morons who see 'lmao' think that the 'l' is actually an uppercase 'I'.
when would 'i' ever mean 'laughing'?
thats like saying 'd' means 'reading'
stupid as hell
ME: lmao, that was funny.
JERK#1(in all caps): IMAO, I AM A MORON!