[编辑] GRE 红宝书
- ［例］ The new law was made retroactive to 1 January.
[编辑] Webster Collegiate
- Etymology: French rétroactif, from Latin retroactus, past participle of retroagere to drive back, reverse, from retro- + agere to drive — more at agent
- Date: 1611
- 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 imposition <retroactive tax>
- ? retroactively adverb
- ? retroactivity noun