Smock, shift (7)
I believe the answer is:
chemise
I believe this clue is a double definition.
'smock' is the first definition.
(I've seen this before)
'shift' is the second definition.
(I know that shift can be written as chemise)
(Other definitions for chemise that I've seen before include "Shift" , "Apron" , "Loose-fitting dress or undergarment" , "Loose dress" , "Loose-fitting dress without a waist" .)