Conservative heads routine church support (6)
I believe the answer is:
crutch
'support' is the definition.
(I've seen this before)
'conservative heads routine church' is the wordplay.
'heads' suggests taking the first letters.
'routine' becomes 'rut' (being stuck in a rut is being stuck in a routine).
'church' becomes 'ch' (common abbreviation).
The initial letter of 'conservative' is 'c'.
'c'+'rut'+'ch'='CRUTCH'
(Other definitions for crutch that I've seen before include "Staff used as an aid to walking" , "Lame walker's aid" , "Support for a disabled person while walking" , "Walking support for lame person" , "supporter" .)