Pernicious / adjective / per·​ni·​cious

Pernicious is an adjective used to describe people or things as harA pernicious person is seen as being subtly wicked or injurious. The effects of being around a pernicious person are often gradual and involve behaviors like gaslighting or outright trickery to achieve their destructive ends. Words like harmful and destructive are synonymous with pernicious.

In a Sentence

The woman was so pernicious that she ruined the lives of every person she came into contact with.

It is advisable to stay as far away from people with pernicious tendencies as you can to preserve your sanity.

If you're wondering how pernicious one person can be, pay attention to the destruction and devastation they leave in their wake.

Etymology

The word pernicious originates from the Latin word pernix, meaning fox. It also relates to other early Latin terms that imply deceitful, insidious, or harmful behavior.

Synonym

Harmful, Destructive

Antonym

Harmless, Innocent