Just hours after the Gypsy King said Wilder can "suck my nuts" ... the Bronze Bomber responded to TMZ Sports -- saying Fury's trash talk is weak, considering Wilder KO'd him in their last fight!!!

"I gave him a memory loss to the point where he don't know how he got on the ground, nor do he know how he got up!"

The two are back trading barbs once again now that Wilder is looking for another opponent after beating Dominic Breazeale's face in over the weekend.

Fury told us Monday he's ready for a rematch, saying he'll take on Wilder anytime, anywhere.

But, when we got Deontay out in NYC ... he didn't seem so sure he wants that to be his next fight ... telling us his no. 1 goal is to be the UNDISPUTED heavyweight champ of the world.

Of course, that would require Wilder to fight Anthony Joshua next -- something both sides clearly want, but have failed to properly negotiate.