The Collaborative International Dictionary of English v.0.48:

Inaccessible \In`ac*cess"i*ble\, a. [L. inaccessibilis: cf. F.
   inaccessible. See In- not, and Accessible.]
   Not accessible; not to be reached, obtained, or approached;
   as, an inaccessible rock, fortress, document, prince, etc. --
   In`ac*cess"i*ble*ness, n. -- In`ac*cess"i*bly, adv.
   [1913 Webster]

WordNet (r) 3.0 (2006):

inaccessible
    adj 1: capable of being reached only with great difficulty or
           not at all [syn: inaccessible, unaccessible] [ant:
           accessible]
    2: not capable of being obtained; "a rare work, today almost
       inaccessible"; "timber is virtually unobtainable in the
       islands"; "untouchable resources buried deep within the
       earth" [syn: inaccessible, unobtainable, unprocurable,
       untouchable]