retroactive

英 [retrəʊ'æktɪv] 美[,rɛtro'æktɪv]

• adj. 追溯的；有追溯效力的；反动的

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;

"retroactive tax increase"

"an ex-post-facto law"

"retro pay"