The act of attempting to rap along with a song--usually a lame, radio hit, only knowing certain parts, and maybe misinterpreting words or phrases.
"You know we--mm-mm-mmm-mm-mm-mmm--all night - this is the life of a coke dealer"
"Dude, it's 'go getta', not 'coke dealer'."
"Are you sure? 'Go getta' sounds lame."
And you don't even know the lyrics. Quit white rapping."