Question: I'm looking for something people from rural area would use, especially when they refer to that person's inability to adapt to the country life.

Answer: 
Per [Wikipedia](https://en.wikipedia.org/wiki/City_slicker):

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> City slicker
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> ***City slicker*** is an idiomatic expression for someone **accustomed to a city or urban lifestyle and unsuited to life in the country**. The term was typically **used as a term of derision by rural Americans** who regarded them with amusement. 
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[![Promotional poster for the movie *City Slickers*, depicting three men in business suits mounted on horses sporting Western-style tack. Billy Crystal is riding his horse backwards, which allows us to see the "I ❤️ NY" bumper sticker on its rump.](https://i.stack.imgur.com/XB6Ct.jpg)](https://i.stack.imgur.com/XB6Ct.jpg)
Toonser

In the North East of Scotland at least. I don't think I've ever heard of it used in anything other than a derogatory manner.

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> *Awa an wash yersel, ya toonser mink.*
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> Away and wash yourself you dirty town dweller.
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<http://www.doricdictionary.com/toonser-noun-urbanite/>