She's a bit of a madam (3)
I believe the answer is:
ada
'she's' is the definition.
'a bit of a madam' is the wordplay.
'a bit of' indicates a hidden word.
'ADA' is hidden within 'madam'.
(Other definitions for ada that I've seen before include "Palindromic girl's name" , "Programming language" , "Girl's name, one letter short of a man's name" , "Novel by Vladimir Nabokov" , "Computer lang.; f. name" .)