Re`tro*act"ive (?), a. [Cf. F. r'etroactif.]
Fitted or designed to retroact; operating by returned action; affecting what is past; retrospective.
Beddoes.
Retroactive law ∨ 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.
© Webster 1913.