Ellington or Wellington (4)
I believe the answer is:
duke
'ellington or wellington' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for duke that I've seen before include "Highest ranked British peer" , "Nobleman of the highest rank" , "noble" , "Highest hereditary title in Britain" , "Highest-ranking nobleman" .)