"King of Rock and Roll" (7)
(Other definitions for presley that I've seen before include "Elvis -, US singer" , "The king of rock 'n roll" .)
'king of rock and roll' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for elvis that I've seen before include "US singer; lives (anag.)" , "Singers Presley or Costello" , "Much-impersonated singer, d. 1977" , "Deceased king of rock 'n' roll" , "'The King' (singer)" .)