look up any word, like ratchet:
 
2.
It means "laughing my head off" and is in reference to an animated GIF of the beheading of American civilian Nick Berg by Iraqi terrorists.

It was popularized after 1justin (me) posted said GIF (created by takumi_) on a large LiveJournal community (indiefucks). Predictably, much drama ensued.
DON'T GET IN OVER YOUR HEAD lmho
by 1justin May 15, 2004
 
1.
Laugh. My. Head. Off
Lmho, I just saw this man with this bright pink leggings and tiger stripes.
by Ryanelle May 25, 2012
 
3.
laughing my heiny off; an Internet abbreviation used to express much laughter

lmho is typically used much less frequently than lmao and lmbo. These two are, for the most part, used much more often.
Person A: They should make a vinyl record of history.
Person B: Really? What would be on it?
Person A: I'm not sure. But it would go at 100 revolutions per minute! *Rimshot*
Person B: LMHO!
by Indog March 14, 2005
 
4.
abbreviation for laughing my hair off
Person#1: hey did you see what janet wore last night?
Person#2: LMHO yes it was funny as fuck!
by Bena and Alex September 22, 2007
 
5.
means "laughing my HYNEEKINS off!" (a lot of people say 'hynee' but i say HYNEEKINS!)

usually used by people who dont cuss, and are just TOO COOL to say "lmbo"
tay: I can read minds, i must be bulemic!
jen: ***bulimic. WHY DO YOU AND LAURELLZ MAKE SO MANY TYPOS?
laurellz: LMHO WYAT ARF TOI TALIING ABIUT?!