Used by people on the net who think adding ness to lol makes it funnier. They are fools. There are also such things as Lolish and Lolness which are similar in their stupidity.
Most people who use it say they made it up.
Fools.

Lolness is the word lol
which means "laugh out loud"
it is describing lol as a ness

the word lol (laugh out loud) wit ness added on the end of it for special effect made up by me an used all around the country now **im 2 cool**

An abbreviation that stands for 'laugh out loud' to you, but 'lots of love' for your mom.

Loyalty Over Law (LOL)
Means to be loyal to the street not to the police

It's original definition was "Laughing out loud" (also written occasionally as "Lots of Laughs"), used as a brief acronym to denote great amusement in chat conversations.

Now, it is overused to the point where nobody laughs out loud when they say it. In fact, they probably don't even give a shit about what you just wrote. More accurately, the acronym "lol" should be redefined as "Lack of laughter."

Depending on the chatter, its definition may vary. The list of its meanings includes, but is not limited to:
1) "I have nothing worthwhile to contribute to this conversation."
2) "I'm too lazy to read what you just wrote so I'm typing something useless in hopes that you'll think I'm still paying attention."
3) "Your statement lacks even the vaguest trace of humor but I'll pretend I'm amused."
4) "This is a pointless acronym I'm sticking in my sentence just because it's become so engraved into my mind that when chatting, I MUST use the meaningless sentence-filler 'lol.'"

See: lmao, lmfao, rofl, lawl, heh, haha, lolol, and 120 for similarities.

used to make something sound less serious or more of a joke even if it's not. similarly used: haha, lmao, lmfao