Invulnerable

a.	1.
	1.	Incapable of being wounded, or of receiving injury. Neither vainly hope To be invulnerable in those bright arms. - Milton.
	2.	Unanswerable; irrefutable; that can not be refuted or convinced; as, an invulnerable argument.

Adj.

1.

invulnerable - immune to attack; impregnable; "gunners raked the beach from invulnerable positions on the cliffs" Antonyms: vulnerable - susceptible to attack; "a vulnerable bridge"

armed, cloaked, copyrighted, covered, deathless, defended, dependable, fail-safe, firm, guaranteed, guarded, harmless, immortal, impenetrable, imperishable, impregnable, incontestable, incorruptible, indelible, indestructible, ineffaceable, ineradicable, inexpugnable, inextinguishable, insuperable, inviolable, irresistible, nonperishable, overpowering, overwhelming, patented, policed, protected, quenchless, reliable, resistless, riskless, safe, safeguarded, screened, sheltered, shielded, sound, stable, steady, trustworthy, unbeatable, undampable, undangerous, undefeatable, undestroyable, undying, unhazardous, unperilous, unprecarious, unquenchable, unrisky, unsubduable, unsurmountable, unyielding, warranteed