None other than (4)
I believe the answer is:
only
'none other than' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for only that I've seen before include "Siblingless (child)" , ". . . . the Lonely (sung by Roy Orbison)" , "Simply" , "Exclusive - individual" , "See 6" .)