Make stronger appeal (notes for parish priest) (6)
I believe the answer is:
anneal
'make' is the definition.
The definition and answer can be both related to change as well as being verbs in their base form.
Maybe there's an association between them I don't understand?
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for anneal that I've seen before include "get tough" , "toughening process" , "Temper by heat treatment" , "Toughen by a process of gradually heating and cooling" , "Destress using heat" .)