Synonyms of impervious

1 Syllable

firm, firms, tight

2 Syllables

jellied, firmest, proofer, safest, gloppy, rainproof, home-free, safer, leakproof, firmer, no-go, no-way, noway, stoical, sealed

3 Syllables

unsocial, waterproof, durable, unmoved, watertight, diuturnal, immune, fine-grained, resistant, nonporous, uncaring, vitrified, hermetic, unruly, padlocked

4 Syllables

unthreatened, imperviable, unpierceable, unaroused, unimpressed, unaffected, impossible, impassive, unreachable, ungettable, unmolested, resistive, indifferent, long-continued, close-grained, impermeable, indocile, impassable, unworkable

5 Syllables

incompressible, inapproachable, unapproachable, unreceptive, impenetrable, invulnerable, inaccessible, unattainable, irrealizable, unachievable, unobtainable, unrealizable