gruesome Share definition Flag An abreviation for great, cool, and awesome. Mostly used by Goths, in a positive manner. Goth boy: Hey look at my new hair style. Goth chick: Gruesome! I love it. Goth boy: Thank you. gruesome by October_Nocturne January 16, 2008 0 0 Get merch Get the gruesome mug. Buy Now — $32.95 See more merch