Madame Curie (5)
I believe the answer is:
marie
'madame curie' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for marie that I've seen before include "girl" , "-- Curie, scientist" , "Queen, guillotined in 1793" , "-- Antoinette" , "French queen, d.1793" .)