ex post facto
"ex-post-facto" is a 11-letter English headword indexed on PlainSpell.
The verdict
“ex post facto” is uncommon English (outside the top frequency list), classed as an adjective. The kind of spelling people second-guess.
- Unranked
- below top-frequency English
- 13
- letters
According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Retroactive.
Corpus desk
Index EN-ex-post-facto · ex post facto · English
ex post facto · unranked · 0 variants · 0 confusables
- FREQ-UNRANKED Unranked
- LEN-MEGA 13 letters
- VOW-4 4 vowels
- CONFUS-0 No pairs
- VAR-0 0 variants
- BOOK-THIN "E" thin
- PHOTO-UNK Peer pending
Read with this headword: Spelling guide for this pattern
Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.
| Property | Value |
|---|---|
| Headword | ex post facto |
| Language | English |
| Part of speech | Adjective |
| Letters | 13 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Long-tail rank of “ex post facto” in English
Rare enough to double-check
ex post facto is uncommon English outside the top frequency list, classed as anadjective. Rarity is why readers land here mid-draft. 2 senses are on record.
The misspelling generator found no plausible variants for ex post facto, and the word's spelling is regular enough that our generator found nothing worth flagging. We don't track a confusable pairing for this entry, since its spelling is unusual enough that it doesn't cluster with a lookalike.
Etymologically, the entry records: From Latin ex (“from”) + post (“after”) + facto, ablative of factum (“deed”). In Latin, ex takes the ablative case, while post takes the accusative case. (See Wikipedia for a discussion of the grammatical form and usage of this phrase.) The correct English form is ex post facto, spelled E-X- -P-O-S-T- -F-A-C-T-O.
Definition
- 1Retroactive.
- 2Retroactive.
Recorded use
Wiktionary examplesThese source excerpts show how ex post facto appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.
One of them added that it was hard lines that there wasn’t any gentleman “such-like as yourself, squire,” to show some sort of appreciation of their efforts in a liquid form; […] The opportunities of acquiring an abnormal thirst had been here limited; a noble use of them had, however, been made, and again I was compelled to deal with the result in an ex p…
Coupled with the Constitution's proscription of ex post facto laws is a similar prohibition against bills of attainder.
Etymology
From Latin ex (“from”) + post (“after”) + facto, ablative of factum (“deed”). In Latin, ex takes the ablative case, while post takes the accusative case. (See Wikipedia for a discussion of the grammatical form and usage of this phrase.)
Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA). See the methodology for how each field is sourced and updated.