indomitable

Incapable of being overcome, subdued, or vanquished; unconquerable.

That cannot be tamed, subdued, or repressed; untamable: applied chiefly to human beings and their attributes: as, indomitable energy, obstinacy, courage, etc.

Not to be subdued; untamable; invincible.

Incapable of being subdued, overcome, or vanquished.

impossible to subdue