The Collaborative International Dictionary
Retroactively \Re`tro*act"ive*ly\, adv. In a retroactive manner.
Wiktionary
adv. Done after the fact; applying to events that have previously transpired.
WordNet
adv. after the fact; "he will get paid retroactively"
Usage examples of "retroactively".
I should point out, however, that such a decision on your part will have the most serious postwar repercussions if, as I confidently expect, my actions are retroactively approved by the Assembly.
This way of doing it did not even have a name at the time, but when, much later, an alternative became available, it was retroactively dubbed the Command Line Interface.
I'll only say that before it was over, approximately fifty percent of the state senators of Sunshine had resigned in disgrace, the White Dome itself had a political black eye because of its covert involvement, I was retroactively exonerated, my drug program was reinstated, a grand jury set out in pursuit of the mysteriously missing warehouse money, and I was launched into my candidacy for the office of the president of the United States of Jupiter.