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Webster 1828 Edition

, a.

Not tracked; not marked by footsteps.

Not followed by the tracks.

untracked ‎(comparative more untracked, superlative most untracked)

Not tracked.
(of a vehicle) Without tracks.
- 1954, The Chartered Mechanical Engineer (page 62)
  What could be more silent and efficient for carrying an untracked vehicle than the pneumatically-tyred wheel?
(of a ski slope) Covered by freshly fallen, undisturbed snow.