Curmudgeon has to get over repair (10)
I believe the answer is:
crosspatch
'curmudgeon' is the definition.
(I've seen this before)
'get over repair' is the wordplay.
'get over' becomes 'cross' (synonyms).
'repair' becomes 'patch' (patching is a kind of repairing).
'cross'+'patch'='CROSSPATCH'
'has to' acts as a link.
(Other definitions for crosspatch that I've seen before include "Grumpy person" , "peevish person" , "Ill-natured type" , "Grumpy type" , "Irascible type" .)