Runners touch, with third (or fourth) moving into first place (4)
I believe the answer is:
skis
'runners' is the definition.
(ski is a kind of runner)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for skis that I've seen before include "More than one runner" , "Engages in a winter sport" , "Snow runners" , "Travels on snow" , "On these in slalom" .)