Perfidious vs. Pernicious — What's the Difference?

Deceitful and untrustworthy

Pernicious is a Thai-American supernatural horror film directed by James Cullen Bressack, who also wrote the story along with co-writer Taryn Hillin. The film stars Ciara Hanna, Emily O'Brien, and Jackie Moore.

Of, relating to, or marked by perfidy; treacherous.

Tending to cause death or serious injury; deadly

Of, pertaining to, or representing perfidy; disloyal to what should command one's fidelity or allegiance.

Causing great harm; destructive

Guilty of perfidy; violating good faith or vows; false to trust or confidence reposed; teacherous; faithless; as, a perfidious friend.

Causing much harm in a subtle way.

Involving, or characterized by, perfidy.

Causing death or injury; deadly.

Tending to betray; especially having a treacherous character as attributed to the Carthaginians by the Romans;

(obsolete) swift; celeritous.

Quick; swift (to burn).

Having the quality of injuring or killing; destructive; very mischievous; baleful; malicious; wicked.

Exceedingly harmful

Working or spreading in a hidden and usually injurious way;