The Collaborative International Dictionary of English v.0.48:

Inescapable \In`es*cap"a*ble\, a.
   Not escapable.
   [1913 Webster]

WordNet (r) 3.0 (2006):

inescapable
    adj 1: impossible to avoid or evade:"inescapable conclusion";
           "an ineluctable destiny"; "an unavoidable accident" [syn:
           ineluctable, inescapable, unavoidable]

Moby Thesaurus II by Grady Ward, 1.0:

25 Moby Thesaurus words for "inescapable":
   certain, fated, fateful, indefeasible, ineluctable, ineludible,
   inevasible, inevitable, inexorable, inflexible, irresistible,
   irrevocable, necessary, relentless, resistless, sure,
   sure as death, sure as fate, unavoidable, uncontrollable,
   undeflectable, unevadable, unpreventable, unstoppable,
   unyielding