Wiktionary
fully well
adv. ''Alternative form of full well''
Usage examples of "fully well".
I knew we had no spare sail for the yard in our hold, but I set sail anyway, knowing fully well if we encountered a storm .
He'd known fully well that Selar had been dissatisfied with his prep work in sickbay, and he had been perfectly candid about the fact that he thought Selar was being too hard on him.