Done after the fact; applying to events that have previously transpired.

Extending in scope, effect, application or influence to a prior time or to prior conditions

The state or condition of being retroactive.

Any action that has an influence due to a past event / An opposing action; a reaction

The state or characteristic of being retroactive. / (law) The application of a law to events that took place before it was made.

plural of retroaction

present participle of retroact

To act backward, or in return; to act in opposition; to be retrospective.

Third-person singular simple present indicative form of retroact

simple past tense and past participle of retroact