Plain, quiet, less stuffy royal brought to the fore (7)

I believe the answer is:

prairie

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'plain' is the definition.
(type of plain)

I cannot understand how the remainder of the clue works.

(Other definitions for prairie that I've seen before include "Extensive US grassland" , "Cowboy song: ` `Bury me not on the lone .......' '" , "Open grassland in the USA" , "Great grassland area" , "Large open area of grassland in the US" .)

I've seen this clue in The Independent.

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