Note: Relevant definitions are in bold letters.
Да уж что! = Let it go; drop it.(just forget about it)
Да -
1.) (part.) yes,oh,indeed,now,well
2.) and, but.
Уж -
1.) (n.)Masc. - Grass snake
2.) sin.;adv. Уже ;
3.) n.Fem - indeed, well; do, be (+ verb)
Что - pn. what,that,which,how,why,like.
From a short story by Dostoevsky:
::escribing something disgusting:::
Совершенно зеленая и... ну, да уж что!
Absolutely green and... well, let it go!