Retroactive
Retroactive , adjective
[Compare French rétroactif.]
Fitted or designed to retroact; operating by returned action; affecting what is past; retrospective. — Beddoes
Collocations (1)
Retroactive law or Retroactive statute (Law) , one which operates to make criminal or punishable, or in any way expressly to affect, acts done prior to the passing of the law.