[1] : WordNet (r) 2.0

unobtainable
     adj : 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, unprocurable, untouchable
see also:
inaccessible unprocurable untouchable 

[2] : Moby Thesaurus II by Grady Ward, 1.0

18 moby thesaurus words for "unobtainable":
   beyond reach, closed forever to, closed to, impenetrable,
   impervious, inaccessible, lost to, out of reach, un-come-at-able,
   unaccessible, unapproachable, unattainable, unavailable,
   undiscoverable, ungettable, unprocurable, unreachable,
   unsecurable

Unobtainable >> U Words
Unobtainable, definition of term: Unobtainable
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