When someone or something demonstrates at an exceptional or supreme level the ability to be "gangster" or a "goon."
Seth Lockhart wore all blue to represent for the Crypts. He looked goontastic at the basketball game.
by Xedious February 28, 2010
1 more definition
In terms of being a Goon, goontastic is the way to describe the ultimate goon.
Yep theyre having a goontastic time next door.
by amethyst79 November 10, 2006