per ‧ me ‧ a ‧ ble /ˈpɜːmiəb ə l $ ˈpɜːr-/ BrE AmE adjective technical
material that is permeable allows water, gas etc to pass through it OPP impermeable :
the permeable cell membrane
—permeability /ˌpɜːmiəˈbɪləti, ˌpɜːmiəˈbɪlɪti $ ˌpɜːr-/ noun [uncountable]