(1) The property or state of being permeable (as by osmosis or diffusion).
(2) The property of a porous material to permit a liquid or gas to pass through.
(3) (geology) The ability of a rock, soil or sediment to transmit water.
(4) (physics) Magnetic permeability.
Word origin: LL permeābilis, equiv. to permeā(re) to permeate.
Related forms: permeable (adjective).