perfidious was our Word of the Day on 07/11/2010. Hear the podcast!
Theme music by Joshua Stamper ©2006 New Jerusalem Music/ASCAP
Examples of perfidious in a Sentence
We were betrayed by a perfidious ally.
a perfidious campaign worker revealed the senator's strategy to his leading rival for the nomination
Recent Examples of perfidious from the Web
Even by that relatively late date, when the authoritarian nature of the regime was already clear, Jacobin was defending it against its perfidious neoliberal critics.
Unsurprisingly, many ordinary Americans came to see themselves as victims of perfidious conspiracies, channeling their energies into indignant rebellions like the Anti-Masonic Party.
Their allegiance was met by this unholy alliance of perfidious greed devolving rapidly into the audacity of vituperative unparalleled predatory rapacity.
The problem isn’t that Obama and Clinton and Trump and whoever else are all perfidious backstabbers who have betrayed the anti-intervention movement.
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'perfidious.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
Did You Know?
We wouldn't lie to you about the history of "perfidious" - even though the word itself suggests deceitfulness. The modern English meaning of "perfidious" remains faithful to that of its Latin ancestor, perfidus, which means "faithless." English speakers have used "perfidious" to mean "treacherous" since at least 1572. One of the earliest known uses of the term can be found in Act V, scene iii of Shakespeare’s All's Well That Ends Well: the "perfidious slave" Parolles is thought to be an unreliable witness; he’ll say whatever suits his purpose, whether true or not. In contemporary usage, "perfidious" not only implies treacherousness, but an inability to be reliable or honorable.
First Known Use of perfidious
Synonymsdisloyal, false, fickle, inconstant, faithless, recreant, traitorous, treacherous, unfaithful, untrue
Antonymsconstant, dedicated, devoted, devout, down-the-line, faithful, fast, loyal, staunch (also stanch), steadfast, steady, true
Related Wordsirresponsible, trustless, undependable, unreliable, untrustworthy; faltering, hesitant, vacillating, wavering; dubious, irresolute, uncertain; apathetic, dispassionate, uninterested
Near Antonymsdependable, dutiful, reliable, responsible, solid, tried, tried-and-true, trustable, trustworthy, trusty; unfaltering, unhesitating, unwavering; determined, intent, resolute; confirmed, dyed-in-the-wool, inveterate, sworn; ardent, avid, enthusiastic, fervent, fervid, impassioned, passionate
Synonym Discussion of perfidious
- faithless allies
- betrayed by false friends
- disloyal to their country
- traitorous acts punishable by death
- a treacherous adviser
- a perfidious double-crosser
PERFIDIOUS Defined for English Language Learners
Seen and Heard
What made you want to look up perfidious? Please tell us where you read or heard it (including the quote, if possible).