Emma left with a man (4)
I believe the answer is:
male
'a man' is the definition.
(thesaurus)
'emma left with' is the wordplay.
'with' indicates a hidden word.
'MALE' is hidden within 'emma left'.
(Other definitions for male that I've seen before include "A gender" , "As are drakes, bulls etc." , "Lame sort of fellow" , "Maldives capital; masculine" , "man?" .)