| Pestilential (a.) Causing death or disease; noxious; pernicious. Thesaurus Entries aggravative, annoying, bothering, bothersome, contentious, disturbing, exasperating, exasperative, galling, harassing, importunate, importune, irking, irksome, irritating, pesky, pestering, pestiferous, pestilent, pestilential, plaguesome, plaguey, plaguing, provocative, provoking, teasing, tiresome, tormenting, troublesome, troubling, vexatious, vexing, wearisome, worrisome, worrying | ![]() |