Definition of "pestilentially"

For a conclusion, I shal only point you to some few more spots which appeare here and there in the body of the Gangrene, which plainly shew the very vitals & inward parts of it to be pestilentially infected;

1646, John Goodwin, Cretensis: or A Briefe Answer to an Ulcerous Treatise‎, London: Henry Overton, page 47

[…] folly and prejudice have spread themselves so pestilentially among all ranks and denominations; that any person, who now would endeavour to benefit his country from a praiseworthy principle of integrity […] the patriot would be hooted at for a madman,

1763, George Alexander Stevens, “Interlude between the Acts”, in The Dramatic History of Master Edward‎, London: T. Waller, page 107

There was a pipe in it [the water closet] but no water, and I say without fear of challenge that it was pestilentially dirty.

1917, M. K. Gandhi, “Third Class in Indian Railways,” communication to the press on 25 September, 1917, Bhadarkali-Lahore: Gandhi Publications League, 1917, p. 5