Scarf in the window (4)
I believe the answer is:
sash
I believe this clue is a double definition.
'scarf' is the first definition.
(I've seen this before)
'window' is the second definition.
(I've seen this before)
'in the' is the link.
(Other definitions for sash that I've seen before include "Style of window" , "Decorative band" , "Band worn over shoulder or round waist" , "Sliding window frame" , "Waistband - type of window" .)