The Collaborative International Dictionary of English v.0.48:

Rancho \Ran"cho\ (r[a^]n"ch[-o]), n.; pl. Ranchos
   (r[a^]n"ch[=o]z). [Sp., properly, a mess, mess room. Cf. 2d
   Ranch.]
   1. A rude hut, as of posts, covered with branches or thatch,
      where herdsmen or farm laborers may live or lodge at
      night.
      [1913 Webster]

   2. A large grazing farm where horses and cattle are raised;
      -- distinguished from hacienda, a cultivated farm or
      plantation. [Mexico & California] --Bartlett.
      [1913 Webster]