Dumbcrap is a word generally used as an insult to another person which is formed from the two words: Dumb and Crap. You are essentially calling someone Dumb and a 'Crap'.
When you get stoned to the point where you're glued to the couch, and can't can't make any truly meaningful contributions to conversation; the term "dumb" refers to both the person's current level of retardation as well as their relative inability to speak.
"Yo I'm bout to go get dumbclapped and watch Rick and Morty"
A group of people that rolls 600 pounds deep, which is really no different than if one person acted like the 600 pound gorilla all by themself, it's just bullying spread around a group to fuck with somebody. Just like each person has an asshole, and to some degree is an asshole, a collective 600 pound gorilla has a collective asshole so that no one person has to take responsibility for being the asshole or the one who said this or that.
A sports team/organization that by all conventional metrics should not have success/wins in whatever activity, but somehow by apparent luck they find a way to win.
example: "The 2013-2014 University of Auburn football team was the team of destiny that year that managed to make it all the way to the championship."