Frame that's worn over shoulder (4)
I believe the answer is:
sash
I believe this clue is a double definition.
'frame' is the first definition.
(sash is a kind of frame)
'that's worn over shoulder' is the second definition.
(Other definitions for sash that I've seen before include "Part of a window - decoration" , "Broad band, the one me father wore?" , "Type of sliding window" , "Ribbon as a symbol of rank" , "Waistband - type of window" .)