The act of being dissed or dissing others. There are levels of gadooree: a slight gadooree, called a paintball gadooree; a middling gadooree, called something along the lines of quadrooree or wommbooree (by a witness, usually directly after after the event happens); and then the worst kind of gadooree, called simply Davey Jones' Locker, referencing a feeling of being at the bottom of the sea, as low as you can go - an ultimately soul-crushing event.
"When a girl laughs at you as you're trying to ask her out"
"When your son makes you play that Disney movie again....and again....and again."
"When someone completely ignores what you're saying"
"Yeah, he's in Davey Jones' Locker after proposing at the Jets game, and being totally rejected"
"Jesus, I am a moron. Wait, is that a self-gadooree?"