Inordinate (5)
I believe the answer is:
undue
'inordinate' is the definition.
(I know that inordinate can be written as undue)
This is all the clue.
(Other definitions for undue that I've seen before include "Lacking justification" , "Improper" , "Excessive amount" , "Excessively, unreasonably" , "Excessive, unreasonable" .)