colossal

Extremely large or on a great scale.

A single puppy can make a colossal mess.

Private-equity nabobs bristle at being dubbed mere financiers.[…]Much of their pleading is public-relations bluster. Clever financial ploys are what have made billionaires of the industry’s veterans. “Operational improvement” in a portfolio company has often meant little more than promising colossal bonuses to sitting chief executives if they meet ambitious growth targets. That model is still prevalent today.

Amazingly spectacular; extraordinary; epic.

"It's just the very biggest thing that I ever heard of!" said I, though it was my journalistic rather than my scientific enthusiasm that was roused. "It is colossal. You are a Columbus of science who has discovered a lost world."