perfidious

[per-fid-ee-uhs] / pərˈfɪd i əs /

ADJECTIVE

treacherous

Synonyms

WEAK

betraying deceitful deceptive double-crossing double-dealing faithless false insidious misleading recreant shifty slick snake in the grass traitorous two-faced two-timing undependable unfaithful unloyal unreliable untrustworthy

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Samuel Pepys knew him; the British diarist thought him “a perfidious rogue.”

From The Wall Street Journal • Mar. 11, 2026

The head of one of them, who preferred to remain anonymous, described it as a "perfidious and effective" strategy.

From Barron's • Nov. 1, 2025

But in the Disney+ series “Agatha All Along,” Hahn pulls from all the disparate strands of her body of work to play the perfidious, power-hungry witch Agatha Harkness.

From Los Angeles Times • Nov. 26, 2024

“If the initial findings are confirmed, it will be a perfidious attack on our electricity infrastructure,” Stübgen said.

From Seattle Times • Mar. 5, 2024

Among the perfidious, the name of traitor is capital in itself.

From "The Left Hand of Darkness" by Ursula K. Le Guin

Vocabulary lists containing perfidious

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