"retroactive" in the adjective sense
1. retroactive
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
affecting things past
"retroactive tax increase"
"an ex-post-facto law"
"retro pay"
Source: WordNet® (An amazing lexical database of English)
Princeton University "About WordNet®."
WordNet®. Princeton University. 2010.
View WordNet® License