A mooyacker is a fat assed looser that likes to talk alot about nonsense, usually shit that no one else but his stupid ass cares about!
That dumb ass mooyacker broke the chair when he sat in it, but he still kept talkin, even after his fat ass hit the ground!The Juice finally said " Shut the fuck up you stupid mooyacker!!!
Somebody who thinks they know everything and know what they're talking about, when in all actuality, they know absolutely nothing. They tell everyone useless facts that they pulled out of their ass to try and sound smart. There is no convincing them that they are wrong.
Person 1: Did you know that if you eat poison oak leaves, you'll never get poison oak?
Person 2: Um... where the fuck did you hear that..