1. relating to or tending to cause pestilence or disease
2. morally corrupting or pernicious
3. extremely annoying or troublesome
Usage: informal

Examples

• The pestilential swamps were breeding grounds for mosquitoes and disease.
• Medieval cities struggled with pestilential conditions due to poor sanitation.
• The critic called the violent video game a pestilential influence on children.
• She found her neighbor’s pestilential habit of playing loud music unbearable.
• The pestilential air in the crowded tenement made residents sick.
• His pestilential attitude poisoned the entire workplace atmosphere.