The track or indication marking the route followed by something that has passed, such as the footprints of animal on land or the contrail of an airplane in the sky.
A route for travel over land, especially a narrow, unpaved pathway for use by hikers, horseback riders, etc.
verb
To follow behind (someone or something); to tail (someone or something).
“The hunters trailed their prey deep into the woods.”
To drag (something) behind on the ground.
“You'll get your coat all muddy if you trail it around like that.”