It means Chuckle. Used when you don't acually laugh out loud. It's more so a suble laugh.
Sam: Did you hear about the new blonde paint?.............It's not real bright, but its cheap, and spreads easy.
by Amandi June 28, 2005
"cackle" - Created as an alternative to the oft exploited "lol", it's used as a brief acronym to denote great amusement in chat conversations.
My dog just ate the neighbor's hamster ckl...
by One Maikru December 02, 2010