Fish trap back in front of church (5)
I believe the answer is:
tench
'fish' is the definition.
(tench is a kind of fish)
'trap back in front of church' is the wordplay.
'trap' becomes 'net' (net is a type of trap).
'back' says the letters should be written backwards.
'in front of' is a charade indicator (letters next to each other) (some letters go in front of others).
'church' becomes 'ch' (abbreviation on maps etc).
'net' written backwards gives 'ten'.
'ten'+'ch'='TENCH'
(Other definitions for tench that I've seen before include "One in school" , "something fishy" , "Swimmer" , "Freshwater fish" , "Coarse fish" .)