Douglas Harper's Etymology Dictionary
Wiktionary
bigass
a. (alternative form of big-ass English)
Usage examples of "bigass".
Hilliard was stationed at the bottom of a hole in the ground where not too long ago, some bigass rocket had been pointed at Moscow or some such city.
The standardbearer is always the first guy into a scrape and he always has one hand tied up keeping a bigass pole from falling over.
These nasty lumps developed all over him, like bigass boils, only when they popped, out came these things.
Had his Remington 700 sniper rifle with a bigass Star-Tron Mark scope on it.