perfidious

[per-fid-ee-uhs]

adjective

1. deliberately faithless; treacherous; deceitful.

   a perfidious lover.

   Synonyms: traitorous, unfaithful, disloyal, false
   Antonyms: faithful

perfidious

/ pəˈfɪdɪəs /

adjective

1. guilty, treacherous, or faithless; deceitful

Other Word Forms

• perfidiously adverb
• perfidiousness noun
• unperfidious adjective
• unperfidiously adverb
• unperfidiousness noun

Word History and Origins

Origin of perfidious¹

First recorded in 1530–40; from Latin perfidiōsus “faithless, dishonest”; perfidy, -ous

Example Sentences

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

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"It was a perfidious act.. and it is a serious war crime, deliberate and intended," the conservative politician said.

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“Behold, campers, this vile and destructive creature! This killer of songbirds! This murderer of chipmunks! This perfidious predator!”

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It ranges from Catholics who want more incense, to Latin Mass adherents who have brought back ancient prayers that mention “the perfidious Jew.”

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Russian President Vladimir Putin's playing a "perfidious" game that "we must not fall for", said Defence Minister Boris Pistorius this week.

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