A term coined by rapper Tech N9ne used at a time of excitement, usually when an attactive woman catches the eye (and vice versa when used by a female, although rare)
Tech N9ne:"I see somethin lookin' good I say Dwam!"
Person 1: "There goes that one girl with the onion booty you gotta just stare"
Person 1&2: (as girl passes) "DWAM!"
To sing with poor skills or no skill at all. ear splitting performance.
"dude, she cannot sing at all!!"
"how bad was she?"
"lookit, dwam, thats how bad she was"