Like trade involving churchgoer in shabby headgear (10)
I believe the answer is:
mercantile
'like trade' is the definition.
(relating to trade)
'churchgoer in shabby headgear' is the wordplay.
'churchgoer' becomes 'rc' (abbreviation for Roman Catholic).
'in' is an insertion indicator.
'shabby' becomes 'mean' (both can mean unkind or unfair).
'headgear' becomes 'tile' (old-fashioned term for a hat).
'rc' placed into 'mean' is 'mercan'.
'mercan'+'tile'='MERCANTILE'
'involving' is the link.
(Other definitions for mercantile that I've seen before include "related to business" , "concerning trade" , "Relating to (overseas) trade" , "Dealing with trade" , "Commercial" .)