Crossword Genius

Friend declared a position (4)

Ross

I believe the answer is:

ally

'friend' is the definition.
(synonyms)

I don't understand how the rest of the clue works.

(Other definitions for ally that I've seen before include "Team up" , "Supporter in a conflict" , "Friend, partner" , "One in cooperation with another" , "Co-operating person or nation" .)

I've seen this clue in The Guardian.
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