Protestant writer travelling to castle (11)

I believe the answer is:

pentecostal

'protestant' is the definition.
(I know that Pentecostal is a type of protestant)

'writer travelling to castle' is the wordplay.
'writer' becomes 'pen' (something which writes).
'travelling' indicates anagramming the letters.
'to'+'castle'='tocastle'
'tocastle' with letters rearranged gives 'tecostal'.
'pen'+'tecostal'='PENTECOSTAL'

(Another definition for pentecostal that I've seen is " Relating to a particular religious festival".)

I've seen this clue in The Telegraph.

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