Pronunciation: (in-vul'nur-u-bul), [key]
1. incapable of being wounded, hurt, or damaged.
2. proof against or immune to attack: A strong navy made Great Britain invulnerable.
3. not open to denial or disproof: an invulnerable argument.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.