permeability

noun

1. (uncountable, usually)The property of being permeable.
2. (uncountable, usually)The rate of flow of a fluid through a porous material.

   “The sulfite cake is usually blended with fly ash (and possibly lime) to produce a landfillable byproduct of low permeability.”

   “McNamara et al. (1991) suggested that neurofactors located within the thoracic ganglion may alter the apparent ionic permeabilities of this freshwater prawn.”

3. (uncountable, usually)A measure of the ability of a rock to transmit fluids (such as oil or water).
4. (uncountable, usually)A quantitative measure of the degree of magnetization of a material in the presence of an applied magnetic field (measured in newtons per ampere squared in SI units).