柯林斯詞典retroactive /?r?tr????kt?v/ 1. ADJ If a decision or action is retroactive, it is intended to take effect from a date in the past. (決定或行爲(wèi))有追溯傚力的[正式] 2. retroactivelyADV [ADV with v] It isn't yet clear whether the new law can actually be applied retroactively. 這項新法令是否具有追溯力還不清楚。 返回 retroactive劍橋詞典If a law or decision , etc. is retroactive, it has effect from a date before it was approved . 有追溯傚力的；溯及既往的 the first British law to have retroactive effect 第一部有追溯傚力的英國法律 返回 retroactive