Influencing or applying to a period prior to enactment: a retroactive pay increase. (adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "retroactive" in a sentence
"Well, I'm not sure this proposal is retrospective I prefer the term retroactive, actually."
"BLITZER: That's what they call retroactive immunity, if you like."
"This is what we call a retroactive confession of evolutionist ignorance, where, as I've observed before, evolutionists exhibit predictable behavior where they "only admit how weak the evidence was for evolution after they have some new allegedly 'transitional' fossil in their hands.""