impervious

UK: /ɪmˈpɜː^rviəs/ US: /ɪmˈpɝviəs/ ,(im pûr′vē əs)

WordReference Random House Learner's Dictionary of American English © 2025

im•per•vi•ous /ɪmˈpɜrviəs/   adj. 

1. not permitting passage through:
   The raincoat is impervious to rain.
2. incapable of being injured or impaired:
   impervious to wear and tear.
3. incapable of being influenced:
   impervious to reason.

im•per•vi•ous•ly, adv. 

WordReference Random House Unabridged Dictionary of American English © 2025

im•per•vi•ous  (im pûr′vē əs), adj. 

1. not permitting penetration or passage; impenetrable:
   The coat is impervious to rain.
2. incapable of being injured or impaired:
   impervious to wear and tear.
3. incapable of being influenced, persuaded, or affected:
   impervious to reason; impervious to another's suffering.

Also, im•per•vi•a•ble  (im pûr′vē ə bəl). 

• Latin impervius. See im-², pervious
• 1640–50

im•per′vi•ous•ly, adv. 
im•per′vi•ous•ness, n. 
Synonyms

• 3. invulnerable, closed.

Collins Concise English Dictionary © HarperCollins Publishers::

impervious / ɪmˈpɜːvɪəs/, imperviable / ɪmˈpɜːvɪəb^əl/ adjective

1. not able to be penetrated, as by water, light, etc; impermeable
2. (often postpositive) followed by to: not able to be influenced (by) or not receptive (to): impervious to argument

imˈperviously adverb

imˈperviousness noun