Church architect’s advanced instrument (6)
I believe the answer is:
wrench
'instrument' is the definition.
(thesaurus)
'church architect's advanced' is the wordplay.
I cannot quite see how this works, but
'church' could be 'ch' (common abbreviation) and 'ch' is located in the answer.
'architect' could be 'wren' (Sir Christopher Wren) and 'wren' is present in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for wrench that I've seen before include "A spanner, or a muscular twist" , "use force" , "Violent twist or pull" , "Jerky pulling movement" , "appliance" .)