term:

Ex Post Facto

ex post facto adv

[Late Latin, literally, from a thing done afterward]
: after the fact
: retroactively [cannot judge ex post facto]
adj 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"]

Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.