Source : Webster's Revised Unabridged Dictionary (1913)

Trek \Trek\, v. i. [imp. & p. p. {Trekked}; p. pr. & vb. n.
   {Trekking}.] [Written also {treck}.] [D. trekken. See
   {Track}, n.] [South Africa]
   1. To draw or haul a load, as oxen.

   2. To travel, esp. by ox wagon; to go from place to place; to
      migrate. [Chiefly South Africa]

            One of the motives which induced the Boers of 1836
            to trek out of the Colony.            --James Bryce.

Trek \Trek\, n. [Written also {treck}.] [D. Cf. {Track}, n.]
   The act of trekking; a drawing or a traveling; a journey; a
   migration. [Chiefly South Africa]

         To the north a trek was projected, and some years later
         was nearly carried out, for the occupation of the
         Mashonaland.                             --James Bryce.

   {Great Trek}, the great emigration of Boers from Cape Colony
      which began in 1836, and resulted in the founding of the
      South African Republic and Orange Free State.

Source : WordNet®

trek
     n 1: a journey by ox wagon (especially an organized migration by
          a group of settlers)
     2: any long and difficult trip
     v 1: journey on foot, especially in the mountains; "We spent the
          summer trekking in the foothills of the Himalayas"
     2: make a long and difficult journey; "They trekked towards the
        North Pole with sleds and skis"
     [also: {trekking}, {trekked}]