Square one for each service option herein? (4)

I believe the answer is:

nine

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

I cannot understand how the remainder of the clue works.

(Other definitions for nine that I've seen before include "So many" , "dancing ladies?" , "Number of Muses and days in a Novena" , "Days Lady Jane 5 ac reigned" , "Cat's lives? - the next clue?" .)

I've seen this clue in The Telegraph.

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