Singer Newton-John (6)
I believe the answer is:
olivia
'singer newton-john' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for olivia that I've seen before include "-- Newton-John, singer" , "- de Havilland, US film actress" , "Female character in Twelfth Night" , "Countess in Twelfth Night" , "Woman" .)