1. In a manner that is harmful, destructive, or morally corrupting; in a way that spreads like a plague or pestilence.
Usage: Formal or literary usage; Often used to describe the spread of ideas, behaviors, or influences

Examples

• The misinformation spread pestilentially through social media.
• His cynical attitude influenced the team pestilentially, undermining morale.
• The disease propagated pestilentially across the region.
• Corruption had pestilentially infected every level of government.
• The rumor spread pestilentially among the students.