Leave out short piece of winter sports equipment (3)
I believe the answer is:
ski
'piece of winter sports equipment' is the definition.
'leave out short' is the wordplay.
'leave out' becomes 'skip' (skipping is a kind of leaving out).
'short' means to remove the last letter.
'skip' with its last letter removed is 'SKI'.
(Other definitions for ski that I've seen before include "Winter sports item" , "Narrow runner for snow and water" , "Move over snow or water" , "Winter sport attachment" , "Snow blade" .)