retroactive

形容词 retroactive:

1. descriptive of any event or stimulus or process that has an effect on the effects of events or stimuli or process that occurred previously
2. affecting things past
   同义词：ex post facto, retro

ret.ro.ac.tive

adj.（形容词）
Influencing or applying to a period prior to enactment:
有追溯效力的：影响或适用于早于颁布的时期的：
例句：
a retroactive pay increase.
应追溯补发的增加工资

来源：
French rétroactif
法语 rétroactif
from Latin retro3ctus [past participle of] retroagere [to drive back]
源自 拉丁语 retro3ctus [] retroagere的过去分词 [驱回]
retrô- [retro-]
retrô- [表示.后.，.向后.]
agere [to drive] * see ag-
agere [驱动] *参见 ag-

【引伸】
ret.roac.tively
adv.（副词）
ret.roactiv.ity
n.（名词）