One hundred articles rejected shortening church (9)
I believe the answer is:
cathedral
'church' is the definition.
(I know that cathedral is a type of protestant cathedral)
'one hundred articles rejected shortening' is the wordplay.
'one hundred' becomes 'C' (Roman numeral).
'articles' becomes 'athe' ('a' and 'the', indefinite and definite articles).
'rejected' says the letters should be written in reverse.
'shortening' becomes 'lard' (I've seen this in another clue).
'lard' reversed gives 'dral'.
'c'+'athe'+'dral'='CATHEDRAL'
(Other definitions for cathedral that I've seen before include "Where one worships" , "Where you'll find bishop" , "Main church of diocese" , "It could hold a large mass" , "place of religion" .)