Synonym Chooser

How is the word treacherous different from other adjectives like it?

Some common synonyms of treacherous are disloyal, faithless, false, perfidious, and traitorous. While all these words mean "untrue to what should command one's fidelity or allegiance," treacherous implies readiness to betray trust or confidence.

a treacherous adviser

When can disloyal be used instead of treacherous?

Although the words disloyal and treacherous have much in common, disloyal implies a lack of complete faithfulness to a friend, cause, leader, or country.

disloyal to their country

When could faithless be used to replace treacherous?

While in some cases nearly identical to treacherous, faithless applies to any failure to keep a promise or pledge or any breach of allegiance or loyalty.

faithless allies

Where would false be a reasonable alternative to treacherous?

The words false and treacherous are synonyms, but do differ in nuance. Specifically, false stresses the fact of failing to be true in any manner ranging from fickleness to cold treachery.

betrayed by false friends

How do perfidious and faithless relate to one another, in the sense of treacherous?

Perfidious adds to faithless the implication of an incapacity for fidelity or reliability.

a perfidious double-crosser

When is traitorous a more appropriate choice than treacherous?

The synonyms traitorous and treacherous are sometimes interchangeable, but traitorous implies either actual treason or a serious betrayal of trust.

traitorous acts punishable by death

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Recent Examples of treacherous The storm could bring hazardous travel, power outages, and treacherous trail conditions during a time of year typically dominated by warmer weather and early summer tourism. Martha McHardy, MSNBC Newsweek, 19 June 2025 Having heard rumors of a mythical doctor (played with a chilling calm by Ralph Fiennes) who could possibly help, Spike sneaks off with her for a treacherous expedition to the mainland. Mark Olsen, Los Angeles Times, 18 June 2025 In a fragmented health-care system like that of the United States, such studies are also commercially treacherous: investors recoil from timelines this long and outcomes this uncertain. Siddhartha Mukherjee, New Yorker, 16 June 2025 Related article Sam Burns is playing free at Oakmont’s treacherous course. Kyle Feldscher, CNN Money, 14 June 2025 See All Example Sentences for treacherous
Recent Examples of Synonyms for treacherous
Adjective
  • Michael Fassbender plays a British intelligence officer tasked with finding who leaked a top-secret software program and betrayed their country, and the list of five potentially traitorous suspects includes his own high-profile wife (Cate Blanchett).
    Brian Truitt, USA Today, 10 May 2025
  • Smith made out their former collaborators to be ungrateful and traitorous, and the kids weren't given the space to question her command.
    Zoey Lyttle, People.com, 18 Apr. 2025
Adjective
  • Prosecutors in the case called for Clayton to be jailed for 10 years, but the defense argued for acquittal –– saying the woman’s testimony had many questions and was unreliable, according to NHK.
    Karina Tsui, CNN Money, 25 June 2025
  • Minimizing unplanned downtime can deliver an impact that becomes amplified when external supply chains are unreliable.
    Ed Garibian, Forbes.com, 25 June 2025
Adjective
  • Simultaneously, Dani Olmo could act as a false number 9 while a Robert Lewandowski believed to be on his way to Saudi Arabia in 2026 is gradually phased out.
    Tom Sanderson, Forbes.com, 24 June 2025
  • This was a false charge by the Bush administration, as the United Nations’ inspectors on the ground in Iraq tried to communicate to Bush, and as his intelligence agencies tried to tell him.
    Tom Zirpoli, Baltimore Sun, 24 June 2025

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Cite this Entry

“Treacherous.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/treacherous. Accessed 7 Jul. 2025.

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