From the M-W Editors
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
First Known Use: 1621
ex post facto
Definition of ex post facto
: done, made, or formulated after the fact : retroactive ex post facto approval ex post facto laws
1787
First Known Use of ex post facto
1787
Law Dictionary
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
ex post facto
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
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