Synonyms: unconquerable
Definition: not capable of being conquered or vanquished or overcome
Usage: a tribute to his courage...and his unconquerable will- R.E.Danielson; faced unconquerable difficulties
Similar words: inexpugnable, impregnable
Definition: incapable of being overcome, challenged or refuted
Usage: an impregnable argument; impregnable self-confidence
Similar words: indomitable, unsubduable, never-say-die
Definition: impossible to subdue
Similar words: insuperable, insurmountable
Definition: impossible to surmount
Similar words: unbeatable, invincible, unvanquishable
Definition: incapable of being overcome or subdued
Usage: an invincible army; her invincible spirit
Similar words: all-victorious
Definition: never having lost
Synonyms: insuperable, unconquerable
Definition: incapable of being surmounted or excelled
Usage: insuperable odds; insuperable heroes
Similar words: unsurmountable, insurmountable
Definition: not capable of being surmounted or overcome
Usage: insurmountable disadvantages