Retroactive



GRE Barron

解释

GRE 红宝书

• adj.溯及既往的;有追溯效力的
• ［例］ The new law was made retroactive to 1 January.

Webster Collegiate

adjective

• 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

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