Dishonourable, mean (7)
I believe the answer is:
ignoble
I believe this is a double definition.
'dishonourable' is the first definition.
(similar in meaning)
'mean' is the second definition.
(similar in meaning)
(Other definitions for ignoble that I've seen before include "Unworthy" , "Completely lacking in character or purpose" , "Base - in globe (anag)" , "I belong (anag)" , "Humble; despicable" .)