| Main Entry: | |
| Part of Speech: | adjective |
| Definition: | unable to be penetrated |
| Synonyms: | closed to, hermetic, immune, impassable, impassive, impenetrable, impermeable, imperviable, inaccessible, invulnerable, resistant, sealed, tight, unaffected, unapproachable, unmoved, unpierceable, unreceptive, watertight |
| Antonyms: | exposed, open, penetrable, responsive, sensitive, vulnerable |