back·side
noun/ˈbæksaɪd/
/ˈbæksaɪd/
(informal)Idioms - the part of the body that you sit on
（人的）屁股蛋子 - Get up off your backside and do some work!
起来干点活儿吧！
- Get up off your backside and do some work!
Idioms
a pain in the backside/arse (British English also)
(North American English also a pain in the ass/butt)
(also a pain in the neck)
- (informal) a person or thing that is very annoying
极讨厌的人（或事物） - That man's a pain in the backside!
这男人真是让人心疼啊！
- That man's a pain in the backside!