Peevish Queen reformed rule over America (9)

I believe the answer is:

querulous

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'peevish' is the definition.
(I've seen this before)

'queen reformed rule over america' is the wordplay.
'queen' becomes 'qu' (abbreviation for queen).
'reformed' indicates anagramming the letters.
'over america' becomes 'ous' (I can't explain this - if you can you should believe this answer much more).
'rule' anagrammed gives 'erul'.
'qu'+'erul'+'ous'='QUERULOUS'

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(Other definitions for querulous that I've seen before include "Cantankerous" , "Plaintive" , "Petulantly complaining" , "Argumentative" , "Carping" .)

I've seen this clue in The Times.

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