Mend with difficulty (3)
I believe the answer is:
fix
This clue is a double definition.
'mend' is the first definition.
('fix' can be a synonym of 'mend')
'difficulty' is the second definition.
(fix is a kind of difficulty)
'with' acts as a link.
(Other definitions for fix that I've seen before include "Repair or attach" , "Arrange" , "Addict's dose of drug" , "Sort out" , "Mend" .)