[ɪmˈpəːvɪəs], (Adjective)

Definitions:
- not allowing fluid to pass through
(e.g: an impervious layer of basaltic clay)

- unable to be affected by
(e.g: he worked, apparently impervious to the heat)


Phrases:

Origin:
mid 17th century: from Latin impervius (from in- ‘not’ + pervius ‘pervious’) + -ous