Flower support (4)
I believe the answer is:
stem
'flower support' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for stem that I've seen before include "Basic skiing turn" , "Stop the flow of, check" , "Thin vertical part of glass or plant" , "Ski turn and plant support" , "Hold back - stock - check" .)