This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

adj. Immune to attack; impregnable.

adj. Impossible to damage, injure, or wound.

adj. Incapable of being wounded, or of receiving injury; not vulnerable.

adj. Unanswerable; irrefutable; unable to be damaged by an attack or convinced; as, an invulnerable argument.

adj. Incapable of being wounded, or of receiving injury.

adj. Unanswerable; irrefutable; that can not be refuted or convinced.

Not vulnerable; incapable of being wounded, hurt, or harmed.

Hence Not to be damaged or injuriously affected by attack: as, invulnerable arguments or evidence.

adj. immune to attack; impregnable

"The more invulnerable the Empire is, the more invulnerable is Canada."

air-tight    defendable    secure    shellproof    unassailable    bombproof    impregnable    inviolable    defensible    sheltered   

vulnerable   

invulnerably    invulnerability   

unanswerable    irrefutable    unassailable    woundless   

vulnerable   

impervious    impregnable    unassailable    indestructible    invincible    valueless    unscathed    unbeatable    nonexistent    unstoppable