# ex post facto

> English word · Adjective

## Definitions
1. Retroactive.
2. Retroactive.

## 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.)

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/ex-post-facto