What is a synonym for impervious?

Here are some synonyms for "impervious," depending on the context:

General synonyms:

* Impenetrable

* Insusceptible

* Unaffected

* Resistant

* Immune

* Unresponsive

* Indifferent

* Unyielding

Synonyms for "impervious to water":

* Waterproof

* Watertight

* Water-resistant

Synonyms for "impervious to persuasion":

* Unpersuadable

* Unyielding

* Inflexible

* Stubborn

Synonyms for "impervious to emotions":

* Cold

* Detached

* Aloof

* Stoic

The best synonym will depend on the specific meaning you want to convey.