Crossword Genius

One of those from Georgia, Trim and one side of the Urals (4)

Ross

I believe the answer is:

asia

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'one' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.

I don't understand the remainder of the clue.

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(Other definitions for asia that I've seen before include "huge territory" , "Continent bordering three oceans" , "Earth's largest continent" , "Continent of the Hindu Kush" , "The Orient" .)

I've seen this clue in the Irish Times.
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