A group said to grow (6)

I believe the answer is:

accrue

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'grow' is the definition.
(I've seen this in another clue)

I can't explain the remainder of the clue.

(Other definitions for accrue that I've seen before include "mount up" , "(Of money) be received in increasing amounts" , "(Of a benefit) be received regularly" , "Gather" , "Increase by periodic additions" .)

I've seen this clue in The Guardian.

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