The most perfidious way of harming a cause consists of defending it deliberately with faulty arguments.
Source: tatoeba (2259)
Perfidious
/pɚˈfɪdi.əs/
Synonyms for "perfidious" (63 found)
Ranked by relevance and common usage.
Closest matches (13)
Strong matches (19)
Related words (31)
falseheartedfoulhypocriticalinsidiousinsincerelyingmachiavellianmercenaryrecreantrenegadeseditiousshiftyslipperytraitoroustreacheroustreasonabletreasonoustrickytwo facedtwo-faced
Show 7 more words
Adjective(4 words)
Choosing the right synonym
- Closest matches in this entry: treacherous, alienated, ambidextrous, artful, bad intention.
- Sentence evidence is available for perfidious, so synonym choice can be checked against real usage rather than a flat word list.
- Ranking signals come from wordnet, opengloss, moby, derived_reverse, and related lexical sources.
Synonym selection checklist
- Match the part of speech before comparing meanings.
- Check whether the synonym changes intensity, formality, or emotional tone.
- Read the replacement inside the full sentence, not just beside "perfidious".
- Prefer the clearest word over the most unusual word when writing for speed or comprehension.
When not to replace "perfidious"
Keep "perfidious" when the sentence already sounds natural, when a synonym would add unintended emphasis, or when readers need the most familiar wording. A synonym should clarify or sharpen the message, not simply make the sentence look more varied.
If two options seem close, choose the one that best matches the audience and purpose of the sentence.
Replacement workflow
1. Preserve meaning
Choose a synonym only if it keeps the core idea of "perfidious" intact in the sentence you are editing.
2. Tune tone
Check whether the replacement sounds more formal, casual, emotional, technical, or forceful than the original word.
3. Re-read context
Read the full sentence after the swap. Keep the synonym only when the sentence becomes clearer or more precise.
Review note: Synonym lists are ranked with lexical data and reviewed for practical writing value. Use the comparison notes, sentence evidence, and source labels together; a high-ranking synonym can still be wrong when the audience, register, or grammar changes.
Final fit check
After choosing a replacement for "perfidious", read the sentence once for meaning and once for rhythm. The best synonym should feel natural in the full sentence, not only accurate in a word list.
If the synonym makes the sentence slower, vaguer, or more dramatic than intended, keep "perfidious" or choose a simpler alternative from the closest-match group.
Related word relations
OpenGloss and ConceptNet supply richer edges like generalizations, collocations, and derivations.
More general
3 entriescharacter traitethical judgementmoral attribute
More specific
4 entriesCollocations
6 entriesperfidious actsperfidious allyperfidious betrayalperfidious conductperfidious deceptionperfidious diplomacy
Inflections
2 entriesmore perfidiousmost perfidious
Derivations
2 entriessimilar
1 entriesSample sentences
9 total sentences available.
By agreeing to integrate the "Tamazight language" into its educational system, the perfidious and calculating Algerian state wants to annihilate the Kabyle language by creating a diglossia which will in turn create serious learning problems and cross-comprehension issues. Because this "Tamazight language" is full of neologisms, in addition to being an absurd mixture of several Berber languages, that often have no meaning and has no connection with the sociolinguistic reality for all Berbers. In the end, they all lose out.
Source: tatoeba (9502746)
Perfidious Albion!
Source: tatoeba (10687552)
I discovered Troy's perfidious plans.
Source: tatoeba (12366870)
Showing 4 of 9 available sentences.
Common questions
What are the closest synonyms for "perfidious"?
Closest matches include treacherous, alienated, ambidextrous, artful, bad intention.
How should I check whether a synonym fits "perfidious"?
Compare the replacement against real sentence context. This entry includes sample sentences so you can check tone, grammar, and meaning before swapping words.