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Definitions

impervious

[im-pur-vee-uhs] / ɪmˈpɜr vi əs /
ADJECTIVE
unable to be penetrated
Synonyms
STRONGEST
immune impassable impenetrable inaccessible invulnerable resistant unaffected unmoved
STRONG
imperviable
WEAK
closed to hermetic impassive impermeable sealed tight unapproachable unpierceable unreceptive watertight
Antonyms
STRONGEST
affected moved susceptible
WEAK
exposed open penetrable responsive sensitive vulnerable

From Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.