Partly devout, mostly extreme (6)

I believe the answer is:

utmost

'extreme' is the definition.
('utmost' can be a synonym of 'extreme')

'partly devout mostly' is the wordplay.
'partly' indicates the answer is hidden within the clue.
'UTMOST' is hidden in the letters of 'devout mostly'.

(Other definitions for utmost that I've seen before include "Furthest or extreme" , "The greatest possible degree" , "Ultimate" , "Extremest" , "At furthest limit" .)

I've seen this clue in The Telegraph.

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