A word created by an utter genius, meaning so awesome that awesome isn't a good enough word. You can also use the term 'awesomefully' which is even better than awesomeful. The best word ever created by humans.
Joe: I'm going to see my favourite band on saturday!
Jim: Awesomeful!
That movie where the Godzillas fight the UFO monsters in the disco while William Shatner battle-raps a potato that slightly resembles John Travolta is awesomeful, like Dan Gardner.