Catholic boy gets dressed (4)
I believe the answer is:
clad
'dressed' is the definition.
(to be clad in something is to be dressed in it)
'catholic boy' is the wordplay.
'catholic' becomes 'C' (abbreviation as in RC for Roman Catholic).
'boy' becomes 'lad' (informal term for boy).
'c'+'lad'='CLAD'
'gets' acts as a link.
(Other definitions for clad that I've seen before include "Wearing" , "Decked" , "Provided with covering" , "Attired" , "Invested" .)