An Etymological Dictionary of Astronomy and Astrophysics

1a) Evidence, as a mark or a series of marks, that something has passed.

1b) A path made or beaten by or as if by the feet of people or animals; trail (Dictionary.com).

1c) A line of motion, a course followed, such as
→ Hayashi track. See also:

→ evolutionary track, → Henyey track, → white dwarf cooling track, → tracking, → tracking accuracy.

2. To follow or pursue the track, traces, or footprints of.

Etymology (EN): M.E. trak, from M.Fr. trac, from O.Fr. trac “track of horses, trace” (mid-15c.), possibly from a Germanic source (compare M.L.G. treck, Du. trek “drawing, pulling).

Etymology (PE): Tor, from Lori, Laki, Fini, Bandar-Abâsi tor “track, trace, mark;” maybe ultimately from Proto-Ir. *tar- “to cross over;” cf. Av. tar- “to cross over;” Mid.Pers. (+*ui-) widur-, widôr- “to pass (beyond, over); Pers. gozar; Baluci tar(r)- “to walk;” Yaghnobi tir-, ter- “to go, leave;” → trans-.
Tor gereftan, with gereftan
“to take, seize” (Mid.Pers. griftan, Av./O.Pers. grab- “to take, seize,” cf.
Skt. grah-, grabh- “to seize, take,” graha “seizing, holding, perceiving,” M.L.G. grabben “to grab,” from P.Gmc. *grab, E. grab “to take or grasp suddenly;” PIE base *ghrebh- “to seize”).