Shearer on the screen (5)
I believe the answer is:
norma
'shearer on the screen' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for norma that I've seen before include "She incited Gauls v. Romans (Bellini)" , "Bellini opera - girl's name" , "Bellini's heroine" , "Girl's name - may be Roman" , "Marilyn was properly one" .)