Source : Webster's Revised Unabridged Dictionary (1913)

Pasture \Pas"ture\, n. [OF. pasture, F. p[^a]ture, L. pastura,
   fr. pascere, pastum, to pasture, to feed. See {Pastor}.]
   1. Food; nourishment. [Obs.]

            Toads and frogs his pasture poisonous. --Spenser.

   2. Specifically: Grass growing for the food of cattle; the
      food of cattle taken by grazing.

   3. Grass land for cattle, horses, etc.; pasturage.

            He maketh me to lie down in green pastures. --Ps.
                                                  xxiii. 2.

            So graze as you find pasture.         --Shak.

Pasture \Pas"ture\, v. t. [imp. & p. p. {Pastured}; p. pr. & vb.
   n. {Pasturing}.]
   To feed, esp. to feed on growing grass; to supply grass as
   food for; as, the farmer pastures fifty oxen; the land will
   pasture forty cows.

Pasture \Pas"ture\, v. i.
   To feed on growing grass; to graze.

Source : WordNet®

pasture
     n 1: a field covered with grass or herbage and suitable for
          grazing by livestock [syn: {pastureland}, {grazing land},
           {lea}, {ley}]
     2: animal food for browsing or grazing [syn: {eatage}, {forage},
         {pasturage}, {grass}]
     v 1: let feed in a field or pasture or meadow [syn: {crop}, {graze}]
     2: feed as in a meadow or pasture; "the herd was grazing" [syn:
         {crop}, {browse}, {graze}, {range}]