perfidy
/ˈpɜː.fɪ.di/
"perfidy" is a 7-letter English headword indexed on PlainSpell.
The verdict
“perfidy” is an uncommon English word, ranked #92,993 in English word frequency and used as a noun.
- #92,993
- frequency rank, English
- 7
- letters
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - A state or act of violating faith or allegiance; violation of a promise or vow, or of trust.
| Property | Value |
|---|---|
| Headword | perfidy |
| Language | English |
| Part of speech | Noun |
| IPA | /ˈpɜː.fɪ.di/ |
| Letters | 7 |
| Frequency rank | #92,993 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “perfidy” sits in English frequency
Spelling & Dictionary Insight
The English entry for perfidy is 7 letters long, classified as a noun, and transcribed in the International Phonetic Alphabet as /ˈpɜː.fɪ.di/. Corpus data places it at rank #92,993 in overall English word frequency, marking it as uncommon enough that many writers pause before typing it. Wiktionary records 3 distinct senses for this headword, so context determines which meaning a reader should apply.
The misspelling generator found no plausible variants for perfidy, which points to an orthography that plays by predictable English rules. Our confusable-pair dataset has no match for it, since nothing in our dataset looks or sounds close enough to cause mix-ups.
Etymologically, the entry records: From Middle French perfidie, from Latin perfidia from perfidus (“faithless, treacherous, false”), from fides (“faith”); related to, for example, English fidelity. The correct English form is perfidy, spelled P-E-R-F-I-D-Y.
Definition
- 1A state or act of violating faith or allegiance; violation of a promise or vow, or of trust.
- 2An illegitimate act of deception, such as using symbols like the Red Cross or white flag in a false claim of surrender to gain proximity to an enemy for purposes of attack.
- 3A state or act of deceit.
Etymology
From Middle French perfidie, from Latin perfidia from perfidus (“faithless, treacherous, false”), from fides (“faith”); related to, for example, English fidelity.
This word in other languages
Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.
Frequently Asked Questions
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Using “perfidy”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is P-E-R-F-I-D-Y - every other letter order is a misspelling in standard orthography.
- Say it as /ˈpɜː.fɪ.di/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
- Browse more English words and confusable pairs in the same reference. English words
Data Source
Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.