Adjective: retroactive ,re-trow'ak-tiv
- Affecting things past
"retroactive tax increase";
- ex post facto, retro
- (psychology) descriptive of any event or stimulus or process that has an effect on the effects of events or stimuli or process that occurred previously
"The retroactive interference of new information affected the recall of previously learned material"
See also: retrospective
Antonym: proactive
Encyclopedia: Retroactive