Modifies a noun

• nuisance: Social reformers near at hand are often intolerable bores and religious fanatics frequently a pestilential nuisance.

• fever: Berkhampstead was visited in 1643 by a violent pestilential fever.

• spot: The pestilential spots appeared chiefly in the neck, breast, and back, and were not easily distinguishable from fleabites.

• state: Many cities also went to ruin, and the famine and pestilential state of the air destroyed thousands of men and cattle.