The Collaborative International Dictionary of English v.0.48:

Inhospitable \In*hos"pi*ta*ble\, a. [Pref. in- not + hospitable:
   cf. L. inhospitalis.]
   [1913 Webster]
   1. Not hospitable; not disposed to show hospitality to
      strangers or guests; as, an inhospitable person or people.
      [1913 Webster]

            Have you no touch of pity, that the poor
            Stand starved at your inhospitable door? --Cowper.
      [1913 Webster]

   2. Affording no shelter or sustenance; barren; desert; bleak;
      cheerless; wild. "Inhospitable wastes." --Blair. --
      In*hos"pi*ta*ble*ness, n. -- In*hos"pi*ta*bly, adv.
      [1913 Webster]

WordNet (r) 3.0 (2006):

inhospitable
    adj 1: unfavorable to life or growth; "the barren inhospitable
           desert"; "inhospitable mountain areas" [ant:
           hospitable]
    2: not hospitable; "they are extremely inhospitable these days";
       "her greeting was cold and inhospitable" [ant: hospitable]

Moby Thesaurus II by Grady Ward, 1.0:

35 Moby Thesaurus words for "inhospitable":
   chill, chilly, closed, cold, cool, disaccordant, disagreeable,
   frosty, icy, ill, incompatible, inimical, strained, tense,
   unaffectionate, unamiable, unamicable, unbenign, unbenignant,
   uncompassionate, uncompassioned, uncordial, unfriendly, ungenial,
   ungracious, unharmonious, unhospitable, unkind, unkindly, unloving,
   unneighborly, unreceptive, unsociable, unsympathetic,
   unsympathizing