Winter sportsperson (5)
'winter sportsperson' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for skier that I've seen before include "Winter sports person" , "needs catching on way down" , "Winter sports athlete" , "He glides over snow, perhaps in sport" , "Slider on snow" .)
(Another definition for snowboarder that I've seen is " One sliding downhill".)