Abbreviated for "Down Low." Sometimes used to say that you are still in the closet. Someone that is afraid to let the world know that they have sex with their homeboys.
Homeboy 1: "Man I like what we really did last night! Your dick is bangin!"
Homeboy 2: "Dude! Shut up! You know I have girlfriend. Don't say that in public, you know i'm on the DL."