Abase (6)
I believe the answer is:
demean
'abase' is the definition.
(I know that demean is a kind of abase)
This is all the clue.
(Other definitions for demean that I've seen before include "Cause (someone) to suffer loss of dignity" , "Stoop" , "Debase" , "Degrade, abase" , "Cause to lose respect" .)