Synonyms For "Invulnerable" :

1 syllable:

safe, strong, tight

2 syllables:

airtight, bombproof, entrenched, secure, shellproof, sheltered

3 syllables:

protected

4 syllables:

defendable, defensible, impregnable, untouchable

5 syllables:

inviolable, unassailable, unattackable, unconquerable