unvanquishable

from WordNet (r) 3.0 (2006)

unvanquishable
    adj 1: incapable of being overcome or subdued; "an invincible
           army"; "her invincible spirit" [syn: {invincible},
           {unbeatable}, {unvanquishable}]

from The Collaborative International Dictionary of English v.0.48

Unvanquishable \Unvanquishable\
   See {vanquishable}.

[email protected]