It grinds audibly as it gets larger (7)

I believe the answer is:

greater

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'larger' is the definition.
('great' can be a synonym of 'large')

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

(Other definitions for greater that I've seen before include "More extensive" , "more influential" , "More renowned" , "more imposing scale" , "more powerful" .)

I've seen this clue in The Globe and Mail.

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