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

Derived Forms

• perˈfidiously, adverb
• perˈfidiousness, noun

Other Words From

• per·fidi·ous·ly adverb
• per·fidi·ous·ness noun
• unper·fidi·ous adjective
• unper·fidi·ous·ly adverb
• unper·fidi·ous·ness noun

Word History and Origins

Origin of perfidious¹

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

Example Sentences

After wreaking a bit of havoc and helping bring Wanda Maximoff’s idyllic small-town family life to an end in “WandaVision,” the Marvel Cinematic Universe’s favorite insidious and perfidious witch will take center stage in “Agatha All Along,” a new spinoff series launching Wednesday on Disney+.

From Los Angeles Times

"Well, why not - let English taxpayers subsidise our free prescriptions, lower rates, no water charges, lower tuition fees and free prescriptions.. but hey, how dare you guys starve us of funding #Perfidious Albion," she wrote.

From BBC

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

From Literature

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

From Seattle Times

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

From BBC