Passes along (6)
I believe the answer is:
relays
'passes along' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for relays that I've seen before include "Rebroadcasts" , "Receives and passes on" , "Passes on a message" , "Foot races in which batons are passed" , "Races where a baton is passed from one to another" .)