Definition of ex post facto in English:

ex post facto

adverb & adjective

  • With retrospective action or force.

    as adjective ‘ex post facto laws’
    backdated, retroactive, ex post facto, backward-looking
    View synonyms

Origin

Erroneous division of Latin ex postfacto ‘in the light of subsequent events’.

Pronunciation

ex post facto

/ˌɛks pəʊst ˈfaktəʊ/