mortal, subtle, galling, pestilential, irritating, pestering, bothersome, venomous, dirty, help, annoying, pesky, corruptive, deathly, plaguelike, baneful, nettlesome, plaguey, plaguy, vexing, perversive, virulent, pestiferous, baleful, lethal, insidious, epidemic, harmful, vexatious, teasing, pernicious
diseased (part of speech: adjective)
unhealthy (part of speech: adjective)
- It had faded from my sight, had grown flat as a dogma, uninteresting as " a foul and pestilent congregation of vapours;" the moon had been but a round thing with the sun shining upon it, and the stars were only minding their own business. - "The Seaboard Parish, Complete", George MacDonald.
- The Countess might have some confederate among them- this pestilent English General, perhaps, who had made himself so conspicuous in her defence; or some one of them might throw light upon her movements, upon her conduct during the journey. - "The Rome Express", Arthur Griffiths.
- A companion, to give him still more encouragement, whispered: Don't mind that pestilent fellow! - "Maximina", Armando Palacio ValdÃ©s.