|1.||D it up|
D it up is most commonly understood as playing very good defense.
"Come on fellas, if we hold them here we'll win the game. It's time to D it up!"
|2.||D it up|
Man, that Chinese food really did a number on me. I gotta go D it up.
He was in the bathroom D-in' it up for like thirty minutes. Must've been a big payload.