1

ex post facto

adverb ex post fac·to \ ˌeks-ˌpōs(t)-ˈfak-(ˌ)tō \

Definition of ex post facto

: after the fact : retroactively

Did You Know?

Ex post facto is Latin for "from a thing done afterward". Approval for a project that's given ex post facto—after the project already has been begun or completed—may just have been given in order to save face. An ex post facto law is one that declares someone's action to be criminal only after it was committed--a procedure forbidden by our Constitution.

Origin and Etymology of ex post facto

Late Latin, literally, from a thing done afterward


2

ex post facto

adjective

Definition of ex post facto

: done, made, or formulated after the fact : retroactive
  • ex post facto approval
  • ex post facto laws

Recent Examples of ex post facto from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'ex post facto.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of ex post facto

1787

in the meaning defined above

See Words from the same year
NEW! Time Traveler

Law Dictionary

1

ex post facto

adverb \ ˈeks-ˌpōst-ˈfak-tō \

legal Definition of ex post facto

: after the fact : retroactively
  • cannot judge ex post facto

Origin and Etymology of ex post facto

Late Latin, literally, from a thing done afterward


2

ex post facto

adjective

legal Definition of ex post facto

1 : done, made, or formulated after the fact : retroactive
2 : of or relating to an ex post facto law
  • the chief concerns of the ex post facto ban
  • —L. H. Tribe

Seen and Heard

What made you want to look up ex post facto? Please tell us where you read or heard it (including the quote, if possible).

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

soothing, mild, or foolish

Get Word of the Day daily email!

Test Your Vocabulary

Name More Food!

Name That Thing

Test your visual vocabulary with our 10-question challenge!

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!