The girls have men’s assistance within (7)
I believe the answer is:
maidens
'the girls' is the definition.
(maiden is a kind of girl)
'men's assistance within' is the wordplay.
'assistance' becomes 'aid' (synonyms).
'within' means one lot of letters goes inside another.
'mens' enclosing 'aid' is 'MAIDENS'.
'have' acts as a link.
(Other definitions for maidens that I've seen before include "Females" , "Misses" , "Unmarried girls" , "bowlers like?" , "Girls in general..." .)