Square indicated by cube here? (4)

I believe the answer is:

nine

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'square' is the definition.
(nine is a square number)

I don't understand the remainder of the clue.

(Other definitions for nine that I've seen before include "Figure" , "One over the eight" , "Number for a club" , "Number of Muses and days in a Novena" , "A stitch in time saves them" .)

I've seen this clue in The Independent.

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