Webster's English Dictionary

Enter the word to look up:

retroactive

re.tro.ac.tive \-'ak-tiv\ \-.ak-'tiv-*t-e-\ aj [F retroactif, fr. L 
   retroactus, pp. of retroagere to drive b]ack, reverse, fr. retro- + agere 
   to drive - more at AGENT : extending in scope or effect to a prior time; 
   esp : made effect ive as of a date prior to enactment, promulgation, or 
   imposition {~) R tax} - re.tro.ac.tive.ly av