Singer ____ John (5)
I believe the answer is:
elton
'singer john' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for elton that I've seen before include "Let on he's John, the singer" , "Sir ___ John, singer-songwriter" , "Sir - - John, singer songwriter" , "First name of singer/songwriter born Reginald Dwight in 1947" , "- John, British singer" .)