Skiing turn (4)
I believe the answer is:
stem
'skiing turn' 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 "Check - part of a plant" , "Main stalk of a plant" , "Originate (from)" , "Restrain - staunch - supporter" , "Ski turn and plant support" .)