Trajectory; thoroughfare (4)
I believe the answer is:
path
This clue is a double definition.
'trajectory' is the first definition.
(I've seen this in another clue)
'thoroughfare' is the second definition.
(thesaurus)
(Other definitions for path that I've seen before include "Way for pedestrians" , "Trodden track" , "trail" , "Track; direction" , "Line of travel" .)