Incense, perhaps of note, mostly of the Catholic Church (5)
I believe the answer is:
aroma
'incense perhaps' is the definition.
(I know that incense is a type of aroma)
'note mostly of the catholic church' is the wordplay.
'note' becomes 'a' (musical note).
'mostly of' means to remove the last letter (I've seen 'mostly' mean this).
'the catholic church' becomes 'Roman' (Roman Catholic Church is an example).
'roman' with its last letter taken away is 'roma'.
'a'+'roma'='AROMA'
'of' is the link.
(Other definitions for aroma that I've seen before include "Fragrance of spices" , "Subtle quality" , "Redolence" , "Perfume" , "Distinctive odour" .)