Perfidious

hard

per-FID-ee-us

adjective

Definition

deceitful and treacherous; disloyal

Examples

The perfidious advisor secretly fed the enemy every detail of the king's plans.
History remembers him as a perfidious ally who broke every treaty he signed.

Synonyms

treacheroustraitorousdisloyalfaithless

Antonyms

loyalfaithfultrustworthysteadfast

Categories

GRE Tip

Perfidious is a hard-difficulty GRE word. On the GRE, you might see it paired with synonyms like "treacherous" or "traitorous" in Sentence Equivalence questions. Look for contrast clues (however, despite, although) that signal the opposite meaning. Words like "loyal".

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