(ˈ)pe|stif(ə)rəs adjective
Etymology: Middle English, from Latin pestifer, pestiferus pestilential, noxious, from pestis plague + -fer, -ferus (from ferre to bear, carry) — more at bear
1. : dangerous to society : pernicious , evil
one of the most pestiferous forms of calumny — Gilbert Burnet
2.
a. : carrying or propagating infection : destructive of health : pestilential
pestiferous vermin
b. : infected with a pestilential disease
poor pestiferous creatures begging alms — John Evelyn
3. : causing annoyance, irritation, or vexation
a pestiferous , high-principled, gimlet-eyed old gentleman — Today
• pes·tif·er·ous·ly adverb
• pes·tif·er·ous·ness noun -es