The act of getting drunk, calling your girlfriend/ boyfriend and arguing over nothing.
Guy 1: Dude where have you been?
Guy 2: ah Sally's being so dumb, we had a liquor and bicker
The act of calling your friends while taking a dump. Usually happens after large meals of the Mexican genre. The dump dialer usually forgets the phone call and or regrets the phone call in the morning.
Oh man I really gotta stop dump dialing when I'm eating.
Dude you dump dialed me last night?