Snowboard cousin (3)
I believe the answer is:
ski
'snowboard cousin' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ski that I've seen before include "Glide or race across snow with feet attachments" , "Slide on blades" , "Glide ove snow" , "Alpine runner" , "Glide on snow with special footwear" .)