Wineglass part (4)
I believe the answer is:
stem
'wineglass part' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for stem that I've seen before include "section of pipe" , "Stalk; stop (flow)" , "Ski turn and plant support" , "part of a ship" , "Hold back - stock - check" .)