Antonyms of adj permeable

1 sense of permeable

Sense 1
permeable (vs. impermeable) -- (allowing fluids or gases to pass or diffuse through; "permeable membranes"; "rock that is permeable by water")

impermeable (vs. permeable) -- (preventing especially liquids to pass or diffuse through; "impermeable stone"; "an impermeable layer of scum"; "a coat impermeable to rain")
        => retentive -- (having the power, capacity, or quality of retaining water; "soils retentive of moisture")
        => water-repellent, water-resistant -- (hindering the penetration of water; "a water-repellent coat")

Similarity of adj permeable

1 sense of permeable

Sense 1
permeable (vs. impermeable) -- (allowing fluids or gases to pass or diffuse through; "permeable membranes"; "rock that is permeable by water")
       => porous -- (able to absorb fluids; "the partly porous walls of our digestive system"; "compacting the soil to make it less porous")
       => semipermeable -- ((of a membrane) selectively permeable)
          Also See-> leaky#1; pervious#1