Answer:
Applying to something in the past
extending in scope or effect to a prior time or to conditions that existed or originated in the past
especially : made effective as of a date prior to enactment, promulgation, or impositio
Explanation:
adjective
(especially of legislation) taking effect from a date in the past.
"a big retroactive tax increase"
https://www.merriam-webster.com/dictionary/retroactive
