Answer Roman Catholic in Bow (3)
I believe the answer is:
arc
'bow' is the definition.
(synonyms)
'answer roman catholic' is the wordplay.
'answer' becomes 'a' (abbreviation eg in Q and A).
'roman catholic' becomes 'rc' (abbreviation for Roman Catholic).
'a'+'rc'='ARC'
'in' is the link.
(Other definitions for arc that I've seen before include "Portion of a circle" , "Electrical spark" , "be rapidly discharged" , "Electric discharge" , "Something used to weld" .)