Fashionably smart young woman docked (4)
I believe the answer is:
chic
'fashionably smart' is the definition.
(I've seen this before)
'young woman docked' is the wordplay.
'young woman' becomes 'chick' (chick is a kind of young woman).
'docked' means to remove the last letter (to dock can mean to remove the tail of an animal).
'chick' with its last letter taken off is 'CHIC'.
(Other definitions for chic that I've seen before include "Elegantly fashionable" , "Stylish and elegant - in France" , "cool" , "Fashionably smart" , "Fashionably elegant" .)