Madison follower (6)
I believe the answer is:
'madison follower' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for monroe that I've seen before include "See 3" , "Marilyn ___ , film icon" , "No more the blond film star" , "No more the old blond film start" , "Marilyn . . . . . ., tragic Hollywood icon" .)