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perfidious

[per-fid-ee-uhs]
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adjective

deliberately faithless; treacherous; deceitful: a perfidious lover.

RELATED WORDS

infidelity, fraud, disloyalty, falseness, disbelief, falsity, dishonesty, treason, betrayal, perfidy, doubt, unfaithfulness, skepticism, treachery, inconstancy

Nearby words

  1. perfectly,
  2. perfecto,
  3. perfector,
  4. perfector press,
  5. perfervid,
  6. perfidiously,
  7. perfidy,
  8. perfin,
  9. perfing,
  10. perfoliate

Origin of perfidious

First recorded in 1590–1600, perfidious is from the Latin word perfidiōsus faithless, dishonest. See perfidy, -ous
ANTONYMS FOR perfidious
faithful.
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Related forms
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for perfidiousness

British Dictionary definitions for perfidiousness

perfidious

adjective

guilty, treacherous, or faithless; deceitful
Derived Formsperfidiously, adverbperfidiousness, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for perfidiousness

perfidious

adj.

1590s, from Latin perfidiosus "treacherous," from perfidia (see perfidy). Related: Perfidiously; perfidiousness.

Online Etymology Dictionary, © 2010 Douglas Harper