unconquerable

from WordNet (r) 3.0 (2006)

unconquerable
    adj 1: not capable of being conquered or vanquished or overcome;
           "a tribute to his courage...and his unconquerable will"-
           R.E.Danielson; "faced unconquerable difficulties" [ant:
           {conquerable}]
    2: incapable of being surmounted or excelled; "insuperable
       odds"; "insuperable heroes" [syn: {insuperable},
       {unconquerable}]

from The Collaborative International Dictionary of English v.0.48

Unconquerable \Unconquerable\
   See {conquerable}.

from The Collaborative International Dictionary of English v.0.48

Unconquerable \Un*con"quer*a*ble\, a.
   Not conquerable; indomitable. -- {Un*con"quer*a*bly}, adv.
   [1913 Webster]

from Moby Thesaurus II by Grady Ward, 1.0

88 Moby Thesaurus words for "unconquerable":
      assiduous, constant, continuing, diligent, dogged, enduring,
      faithful, immutable, impassable, impenetrable, impregnable,
      inalterable, incontestable, indefatigable, indomitable,
      industrious, inexpugnable, insistent, insuperable, insurmountable,
      invincible, inviolable, invulnerable, irresistible, lasting, loyal,
      never-tiring, obstinate, overpowering, overwhelming, patient,
      patient as Job, permanent, perseverant, persevering, persistent,
      persisting, pertinacious, plodding, plugging, preoccupied, proof,
      rapt, relentless, resistant, resistless, resolute, secure,
      sedulous, single-minded, sleepless, slogging, stable, steadfast,
      steady, stubborn, tenacious, tight, tireless, unabating,
      unassailable, unbeatable, undaunted, undefeatable, undiscouraged,
      undrooping, unfailing, unfaltering, unflagging, unflinching,
      unintermitting, uninterrupted, unnodding, unrelaxing, unrelenting,
      unremitting, unsleeping, unsubduable, unsurmountable, unswerving,
      untiring, unwavering, unwearied, unwearying, unwinking, unyielding,
      utterly attentive, weariless