Rise and relax, free of cold (4)

I believe the answer is:

hill

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

I don't understand the rest of the clue.

(Other definitions for hill that I've seen before include "See 8" , "See 14" , "High mass of land" , "Fell" , "Gradient" .)

I've seen this clue in The Guardian.

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