1. A combination of two or more words, objects or actions which are each awesome. The combination of these awesome things has the effect of multiplying the awesomeness of one word, object or action by the awesomeness of the other, creating an thing exponentially more awesome than its component parts. Examples - ghost pirate, space cowboy, robot zombie ninja.
2. A combination of two words, objects or actions which alone are not very awesome, but when combined become awesome. Examples - squirrel shoes, art car, hammer pants.
And then my friend said "granola barrage", which was the best compound awesome I'd heard in months!