permeability

permeabilities

Use the noun permeability to describe how slowly or quickly water soaks into something, particularly soil.

You're most likely to come across the word permeability in an earth science class. The permeability of something means basically the same thing as how absorbent it is — for example, a gravel driveway has much greater permeability than a heavy clay soil does. The root word is the Latin permeabilis, "that can be passed through."