invulnerable

Từ điển WordNet v3.1 - WordNet Dictionary

adjective

immune to attack;
impregnable (Freq. 1)
- gunners raked the beach from invulnerable positions on the cliffs
• Ant:
vulnerable
• Similar to:
airtight, air-tight, bombproof, shellproof, defendable,
defensible, entrenched, impregnable, inviolable, secure, strong,
unassailable, unattackable, tight, sheltered, untouchable
• See Also:
protected, safe, secure, unconquerable
• Derivationally related forms:
invulnerability