Distinctive, with rather large dresses (8)
I believe the answer is:
Here is my best explanation:
'distinctive' is the definition.
'with rather large dresses' is the subsidiary indication.
'with' becomes 'and'.
'rather large' becomes 'stout'.
'dresses' indicates putting letters inside (dress can mean cover).
'and' put inside 'stout' is 'standout'.
(Other definitions for standout that I've seen before include "Persist in opposing" and "project".)