ex post facto

American  

[eks pohst fak-toh] / ˈɛks ˌpoʊst ˈfæk toʊ /

adverb

1. from or by subsequent action; retroactively; subsequently; retrospectively.

---

adjective

1. having retroactive force; made or done subsequently.

   an ex post facto law.

ex post facto British  

/ ɛks pəʊst ˈfæktəʊ /

adjective

1. having retrospective effect

   an ex post facto law

---

ex post facto ¹ Cultural  

1. An explanation or regulation concocted after the event, sometimes misleading or unjust: “Your ex post facto defense won't stand up in court.” (See ex post facto law.) From Latin, meaning “after the deed.”

---

ex post facto ² Cultural  

1. A descriptive term for an explanation or a law that is made up after an event and then applied to it: “The chairman's description of his plan sounds like an ex post facto attempt to justify an impulsive action.” Ex post facto is Latin for “from after the deed.”

---

Etymology

Origin of ex post facto

First recorded in 1625–35; from Latin: “from a thing done afterward, from what is done afterward”

Example Sentences

Ex post facto laws, which impose criminal liability after the crime, are unconstitutional, and the Supreme Court has applied that prohibition to procedural changes, such as statutes of limitations.

From Slate • Mar. 15, 2019

Ex post facto, of course, contractors always have a reason why problems aren’t their fault.

From Slate • Nov. 19, 2013

Ex post facto laws are an abomination, and this committee is not a court.

From Time Magazine Archive

Ex post facto laws, prohibited by Constitution of U.S.,

From The Great Speeches and Orations of Daniel Webster With an Essay on Daniel Webster as a Master of English Style by Webster, Daniel

Ex post facto, at all events, that justification was furnished by the Essays of Montaigne.

From Gaston de Latour; an unfinished romance by Pater, Walter