List hill as showing muscle (7)

I believe the answer is:

rotator

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

'list hill as' is the wordplay.
'list' becomes 'rota' (rota is a kind of list).
'hill as' becomes 'tor' (tor is a kind of hill. I am not sure about the 'as' bit.).
'rota'+'tor'='ROTATOR'

'showing' acts as a link.

Can you help me to learn more?

(Other definitions for rotator that I've seen before include "One goes around" , "this one is for turning" , "One palindromic turner ..." , "Device that spins" , "Revolver" .)

I've seen this clue in The Daily Express.

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