Marilyn —, singer and actress who played Sugar Kane Kowalczyk in 1959 film comedy Some Like It Hot (6)
I believe the answer is:
monroe
(Other definitions for monroe that I've seen before include "FILMSTAR" , "Marilyn . . . . . ., tragic Hollywood icon" , "Marilyn ___ , film icon" , "President < and film star" , "No more the old blond film start" .)