The Collaborative International Dictionary of English v.0.48:

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.]
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            Toads and frogs his pasture poisonous. --Spenser.
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   2. Specifically: Grass growing for the food of cattle; the
      food of cattle taken by grazing.
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   3. Grass land for cattle, horses, etc.; pasturage.
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            He maketh me to lie down in green pastures. --Ps.
                                                  xxiii. 2.
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            So graze as you find pasture.         --Shak.
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The Collaborative International Dictionary of English v.0.48:

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.
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The Collaborative International Dictionary of English v.0.48:

Pasture \Pas"ture\, v. i.
   To feed on growing grass; to graze.
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WordNet (r) 3.0 (2006):

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