Definify.com

Webster 1913 Edition

Noun.

[Cf. F.

invincibilité

The quality or state of being invincible; invincibleness.

Noun.

The quality of being unconquerable; insuperableness.

invincibility ‎(countable and uncountable, plural invincibilities)

state or quality of being invincible

invincibility in The Century Dictionary, The Century Co., New York, 1911
invincibility in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913