To be in an inebriated state of drunkeness, but still able to form a sly grin and light a cigarette to impress your friends. Put more simply, another way of saying "I'm wasted".
Can also be used when not drunk at all purely for humour value, or in anticipation of a drinking session.
Usually when someone is working very hard or when they tell a terrible joke and your being sarcastic that their joke is good
Guy 1- hey bro guess what Guy 2- what
Guy 1-what is fat and goes bump at night
Guy 2-idk what
Guy 1-Ur mom!
Guy 2- wow that joke slapped harder than a weed wacker on a Thursday