Track event (5,4)
I believe the answer is:
relay race
'track event' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for relay race that I've seen before include "Foot speed contest passing batons" , "Team contest" , "having started, one couldn't finish it" , "Speed contest with teams of four runners" , "Ace rarely placed in team event" .)