Note old archdeacon, leader of Anglican prayers (6)
I believe the answer is:
novena
'prayers' is the definition.
(thesaurus)
'note old archdeacon leader of anglican' is the wordplay.
'note' becomes 'n' (abbreviation).
'old' becomes 'o' (abbreviation).
'archdeacon' becomes 'ven' (abbreviation for The Venerable).
'leader of' suggests taking the first letters.
The initial letter of 'anglican' is 'a'.
'n'+'o'+'ven'+'a'='NOVENA'
(Other definitions for novena that I've seen before include "Nine-day religious devotion" , "Nine consecutive days of prayer or worship" , "Catholic nine-day devotion" , "Roman Catholic devotion over nine days" , "Nine-day ritual" .)