The Collaborative International Dictionary of English v.0.48:

Hacienda \Ha`ci*en"da\ ([aum]`th[-e]*[asl]n"d[.a] or
   h[aum]`s[i^]*[e^]n"d[.a]), n. [Sp., fr. OSp. facienda
   employment, estate, fr. L. facienda, pl. of faciendum what is
   to be done, fr. facere to do. See Fact.]
   1. A large estate where work of any kind is done, as
      agriculture, manufacturing, mining, or raising of animals;
      a cultivated farm, with a good house, in distinction from
      a farming establishment with rude huts for herdsmen, etc.;
      -- a word used in Spanish-American regions.
      [1913 Webster]

   2. The main residence of a hacienda[1].
      [PJC]

WordNet (r) 3.0 (2006):

hacienda
    n 1: a large estate in Spanish-speaking countries
    2: the main house on a ranch or large estate