Unwarranted (5)
I believe the answer is:
undue
'unwarranted' is the definition.
(I know that unwarranted can be written as undue)
This is all the clue.
(Other definitions for undue that I've seen before include "Needless; excessive" , "Excessive, unreasonable" , "Excessive - unwarranted" , "Not to be paid" , "Inappropriate - excessive" .)