Synonyms: unbeatable, invincible, unvanquishable
Definition: incapable of being overcome or subdued
Usage: an invincible army; her invincible spirit
Similar words: 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
Synonyms: unbeatable
Definition: hard to defeat
Usage: an unbeatable ball team