Moonstruck Oscar winner (4)
I believe the answer is:
cher
'moonstruck oscar winner' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for cher that I've seen before include "US pop singer" , "Singer; dear (French)" , "US singer; dear (Fr.)" , "Sonny and - -" , "US singer/actress - French river/department" .)