Synonyms of retroactive

Adjective

1. retroactive (vs. proactive)

usage: descriptive of any event or stimulus or process that has an effect on the effects of events or stimuli or process that occurred previously

2. ex post facto, retroactive, retro, retrospective (vs. prospective)

usage: affecting things past; "retroactive tax increase"; "an ex-post-facto law"; "retro pay"

Definition and meaning of retroactive (Dictionary)