Note short skirt (4)
I believe the answer is:
mini
'skirt' is the definition.
(a mini skirt)
'note short' is the wordplay.
'note' becomes 'minim' (type of musical note).
'short' means to remove the last letter.
'minim' with its last letter taken away is 'MINI'.
(Other definitions for mini that I've seen before include "Cult British car" , "Car designed by Issigonis" , "Short skirt - small car" , "type of garment" , "(Car etc) of small size" .)