汉：来源于拉丁语，意为“backward,back”表示：“向后、回、返”
英：prefix meaning "backwards, behind," from L. retro (prep.) "backward, back, behind," probably originally the ablative form of *reteros, based on re- "back" (see re-). Common in combinations in post-classical Latin.
1.retroactive
adj.applying to the past 法律，支付等有追溯效力的；retro=backward,act=act,do
Congress made provisions for the law to be retroactvie to 1989.
议会规定那部法律的条款可追溯到1989年。
2.retrograde
v.decline,revert,grow worse 退步，堕落，恶化
adj.directed backwards;likely to cause worse conditions;deterioation后退的；使倒退的；恶化的
retro=backward,grad=go,degree
Instead of advancing,our Civilization seems to have retograded in ethics and culture.
在伦理和文化上，我们的文明好像不但没有进步，反而倒退了。
3.retrospect
n.view of past events 回顾，回想 retro=backward,spect=look
The film is a retrospect of the investigation into the Kennedy assassination.
这部电影对暗杀肯尼迪总统事件的调查过程进行了回顾。