Routine behaviour in the garb of a Church person (5)
I believe the answer is:
habit
I believe this is a triple definition!
'routine' is the first definition.
(I've seen this before)
'behaviour' is the second definition.
(I have seen 'Ingrained behaviour' mean 'habit' so perhaps 'behaviour' could also mean 'habit')
'in the' acts as a link.
'garb of a church person' is the third definition.
'habit' can be an answer for 'garb' (habit is a kind of garb). I am unsure of the 'of a church person' bit.
Can you help me to learn more?
(Other definitions for habit that I've seen before include "Custom or established practice" , "Usual practice; garment" , "What might one have a regular tendency to" , "addictive practice" , "Riding garment" .)