Source : Webster's Revised Unabridged Dictionary (1913)

Trackless \Track"less\, a.
   Having no track; marked by no footsteps; untrodden; as, a
   trackless desert.

         To climb the trackless mountain all unseen. --Byron.
   -- {Track"less*ly}, adv.-{Track"less*ness}, n.

Source : WordNet®

trackless
     adj 1: having no tracks; "a trackless trolley"; "the trackless
            snowy meadow" [ant: {tracked}]
     2: lacking pathways; "trackless wilderness"; "roadless areas"
        [syn: {pathless}, {roadless}, {untracked}, {untrod}, {untrodden}]