riff raff

基本解释

These people give me the creeps. Riff raff!
这些人使我起鸡皮疙瘩。真是一群痞子！
Western Europe may have cheered the revolution, but it fears a flood of riff-raff from the east.
西欧可能会对革命欢欣鼓舞，但也担心来自东部的贫民潮。
Littered on the grass, we seemed dingy, urban riff-raff. We defiled the scene, like sardine-tins and paper bags on the seashore.
我们呢，却好像是一堆肮脏的城市垃圾，被胡乱丢在草地上，如同海滩上的纸袋和沙丁鱼罐头盒一样败坏风景。

The privileged few who have doormen in their buildings get to have someone to receive their packages and visitors, and keep the riff raff out of the building.
FORBES: Connect
Mad Decent Signee Riff Raff Has A Plan: Eccentric MC and Internet personality Riff Raff spoke with me about how 2013 will be the year he ascends to the top of the rap pack.
FORBES: A Year in Review
In it, Captain Kirk needs to acquire plague-fighting minerals from the planet Ardana, currently in the middle of a civil uprising against a super wealthy and socially elite class that live in a floating city, far above the riff raff.
FORBES: The Rise And Fears Of The New Elite

If you refer to a group of people as riffraff, you disapprove of them because you think they are not respectable.