Ready to take a pew (4)
I believe the answer is:
seat
'pew' is the definition.
(I've seen this in another clue)
'ready to take a' is the wordplay.
'ready' becomes 'set' (set can mean ready or prepared).
'to take' indicates putting letters inside (inserted letters are taken in).
'set' going around 'a' is 'SEAT'.
(Other definitions for seat that I've seen before include "'A chair, say (4)'" , "A manner of sitting on horse" , "Horizontal part of a chair" , "Behind" , "Somewhere to sit" .)