Synonyms of impregnable
- 1 Syllable
- firm, strong
- 2 Syllables
- parlous, safest, home-free, safer, solid, no-win
- 3 Syllables
- tenable, jeopardous, securer, dangerous, secure, bulletproof, fortified
- 4 Syllables
- unthreatened, dangersome, unshakable, unmolested, formidable, invincible
- 5 Syllables
- indomitable, indefeasible, inexpugnable, impenetrable, indestructible, insurmountable, invulnerable, unassailable, unattackable, unconquerable, undefeatable, unsurmountable, unmasterable