Singer Diana ____ (4)
I believe the answer is:
ross
'singer diana' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ross that I've seen before include "US singer Diana" , "- and Cromarty, former Scottish county" , "Diana - (Supremes)" , "Wye town; Antarctic sea" , "Diana --, Motown singer" .)