Defined as laugh wan kill me die, used to denote great amusement in a chat conversation.
Although it's not as popular as LOL(Laugh out loud) , which has been over used to a point it lost it's meaning because nobody really laughs out loud.
Guy: You see wetin Pusha T do Drake? 😂
Guy 2: Yeah! LWKMD!
To know or understand
John: I dey watch Jenifa’s Diary
Mark: O! I sabi know am