Seat in church found by boy (5)
I believe the answer is:
bench
'seat' is the definition.
(I know that seat can be written as bench)
'church found by boy' is the wordplay.
'church' becomes 'ch' (abbreviation on maps etc).
'found by' says to put letters next to each other.
'boy' becomes 'ben' (boy's name).
'ch' after 'ben' is 'BENCH'.
'in' is the link.
(Other definitions for bench that I've seen before include "Magistrates collectively" , "Long seat or worktable" , "Pew or settle" , "Group of magistrates" , "Exhibit at dog show" .)