- (of a substance) not allowing the passage of a fluid through interstices; not permeable
WordReference Random House Learner's Dictionary of American English © 2026
im•per•me•a•ble /ɪmˈpɜrmiəbəl/USA pronunciation
adj.
im•per•me•a•bly, adv.
WordReference Random House Unabridged Dictionary of American English © 2026- Geology, Chemistry(of porous substances, etc.) not permitting a fluid to pass through:The tree cells have an impermeable membrane.
im•per•me•a•bly, adv.
im•per•me•a•ble
(im pûr′mē ə bəl),USA pronunciation adj.
im•per′me•a•bil′i•ty, im•per′me•a•ble•ness, n.
im•per′me•a•bly, adv.
- not permeable;
impassable. - Chemistry, Geology(of porous substances, rocks, etc.) not permitting the passage of a fluid through the pores, interstices, etc.
- Late Latin impermeābilis. See im-2, permeable
- 1690–1700
im•per′me•a•bly, adv.
Collins Concise English Dictionary © HarperCollins Publishers::
impermeable /ɪmˈpɜːmɪəbəl/ adj
'impermeable' also found in these entries (note: many are not synonyms or translations):