Perfidious
hardNegative toneper-FID-ee-us
adjective
Definition
deceitful and treacherous; disloyal
Memory hook
PERFIDIOUS holds 'FID' (faith, as in Fido the faithful dog). Now imagine Fido turned traitor, leading burglars to your house: faith betrayed.
Word roots
Learning roots unlocks whole word families. Study common GRE root words.
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.”
Test yourself
Fill in the blank with the right word:
“The ______ advisor secretly fed the enemy every detail of the king's plans.”
Show answer
perfidious
Synonyms
Antonyms
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".
Related GRE Words
mendacious
given to lying; dishonest
insidious
Proceeding in a gradual, subtle way with harmful effects
abstemious
Moderate in eating and drinking; self-restrained
artifice
Clever or cunning devices or expedients, especially to deceive; trickery
artless
free of guile or pretense; naturally simple and sincere
chicanery
The use of trickery to achieve a political, financial, or legal purpose
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