"lol" is an acronym which stands for "Laughing Out Loud".

Rofl! The others are right. :) In fact, several years ago I didn't know what "lol" meant but I still used it. Because in Dutch we actually have the word "lol" and it means "funny". So a couple of years ago when some English people used the word "lol" I asked them why they were using a Dutch word. That's when I found out about it being acronym.

it also means lot of love x

LOL=Laughing Out Loud=大声笑