Acre's a ground with knight — fighting me? (7)

I believe the answer is:

saracen

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'fighting me?' is the definition.
The definition suggests a singular noun which matches the answer.

'acre's a ground with knight' is the wordplay.
'ground with' indicates an anagram ('grind' the letters into a new form).
'knight' becomes 'N' (chess abbreviation).
'acres'+'a'='acresa'
'acresa' mixed up with 'n' makes 'SARACEN'.

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(Other definitions for saracen that I've seen before include "Ear scan (anag.)" , "Ancient warrior" , "Arab or Muslim at time of the Crusades" , "old Muslim back" , "Crusader's foe" .)

I've seen this clue in The Times.

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