Dishearten with exam in end (10)
I believe the answer is:
demoralise
'dishearten' is the definition.
('dishearten'->'demoralize' is in my internal thesaurus and 'ize'->'ise')
'exam in end' is the wordplay.
'exam' becomes 'oral' (oral exam is a kind of exam).
'in' means one lot of letters goes inside another.
'end' becomes 'demise' (demise is a kind of end**).
'oral' inserted into 'demise' is 'DEMORALISE'.
'with' is the link.
(Other definitions for demoralise that I've seen before include "Make downhearted" , "Cause to lose confidence/hope" , "Throw into confusion" , "Cause to lose confidence" , "Crush" .)