In
music production when something is wet that means they have used alot of
effects on the song or on the particular
track that sounds wet.
also
slang I hear in rap music or in the park while playing chess. When you've been shot in the chest and are covered in blood you're wet or you've been wetted.
"Im gonna wet that chain snatcher" (park)
"straight up, boo, I wetted that bitch" (rap music)