Some overtime in retirement to get fancy church hat (5)
I believe the answer is:
mitre
'hat' is the definition.
(I know that mitre is a type of hat)
'some overtime in retirement' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'in retirement' is a reversal indicator (retire can mean to go back or backwards).
'ertim' is hidden within 'overtime'.
'ertim' in reverse letter order is 'MITRE'.
'to get fancy church' acts as a link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for mitre that I've seen before include "Corner joint - bishop's headdress" , "Corner joint - bishop's hat" , "top?" , "Type of joint - bishop's hat" , "Liturgical headdress" .)