Talk a short time after church (4)
I believe the answer is:
chat
'talk' is the definition.
(chat can mean to talk)
'a short time after church' is the wordplay.
'short time' becomes 't' (abbreviation for time).
'after' is a charade indicator (letters next to each other).
'church' becomes 'ch' (common abbreviation).
'a'+'t'='at'
'at' after 'ch' is 'CHAT'.
(Other definitions for chat that I've seen before include "Gossip" , "Talk easily; songbird" , "gas" , "Talking" , "Rabbit" .)