Newcomer in religious order, one they ordered to keep quiet (8)
I believe the answer is:
neophyte
'newcomer in religious' is the definition.
'neophyte' can be an answer for 'newcomer' (synonyms). I am not certain of the 'in religious' bit.
'order one they ordered to keep quiet' is the wordplay.
'order' is an anagram indicator.
'ordered' indicates anagramming the letters.
'to keep' indicates putting letters inside.
'quiet' becomes 'p' (music symbol for 'piano', ie soft or quiet).
'they' is an anagram of 'hyte'.
'hyte' enclosing 'p' is 'phyte'.
'one' with letters rearranged gives 'neo'.
'neo'+'phyte'='NEOPHYTE'
Can you help me to learn more?
(Other definitions for neophyte that I've seen before include "Initiate" , "Beginner, novice" , "Newcomer, starter" , "raw recruit" , "Pet honey for a religious novice" .)