permeability

American  

[pur-mee-uh-bil-i-tee] / ˌpɜr mi əˈbɪl ɪ ti /

noun

1. the property or state of being permeable.

2. Also called magnetic permeability.  Electricity. a measure of the change in magnetic induction produced when a magnetic material replaces air, expressed as a coefficient or a set of coefficients that multiply the components of magnetic intensity to give the components of magnetic induction.

3. Geology. the capability of a porous rock or sediment to permit the flow of fluids through its pore spaces.

4. Aeronautics. the rate at which gas is lost through the envelope of an aerostat, usually expressed as the number of liters thus diffused in one day through a square meter.

5. Nautical. the capacity of a space in a vessel to absorb water, measured with reference to its temporary or permanent contents and expressed as a percentage of the total volume of the space.

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permeability British  

/ ˌpɜːmɪəˈbɪlɪtɪ /

noun

1. the state or quality of being permeable

2.  μ.  a measure of the response of a medium to a magnetic field, expressed as the ratio of the magnetic flux density in the medium to the field strength; measured in henries per metre See also relative permeability magnetic constant

3. civil engineering the rate of diffusion of a fluid under pressure through soil

4. the rate at which gas diffuses through the surface of a balloon or airship, usually expressed in litres per square metre per day

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permeability Scientific  

/ pûr′mē-ə-bĭl′ĭ-tē /

1. The ability of a substance to allow another substance to pass through it, especially the ability of a porous rock, sediment, or soil to transmit fluid through pores and cracks. Geologic permeability is usually measured in millidarcies.

2. See more at darcy

3. Magnetic permeability.

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Usage

What does permeability mean? Permeability is the quality or state of being permeable—able to be penetrated or passed through, especially by a liquid or gas. The verb permeate means to penetrate, pass through, and often become widespread throughout something. Similar words are pervade and saturate. Permeate can be used both in the context of the physical spread of something within a space and in more figurative ways. Water permeates the soil. Dye permeates fabric. An idea can permeate someone’s mind. In these cases, the fabric and the mind could be described as permeable. Things that are permeable have different levels of permeability. For example, certain materials may easily absorb liquid, while others may only allow small amounts of liquid to permeate their surface. The word permeability is used in several more specific ways in the context of ships, aircraft, electricity, and geology. Example: This type of stone was chosen for its permeability—it absorbs water.

Other Word Forms

Derived Forms

• nonpermeability
  noun

Etymology

Origin of permeability

First recorded in 1750–60; perme(able) + -ability ( def. )

Explanation

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."

Example Sentences

Permeability is important because it influences the delicate dance between carbon dioxide and lactic acid bacteria.

From Scientific American • May 16, 2023

Permeability is a measure of the interconnectedness of pores in a rock or sediment.

From Textbooks • Jan. 1, 2017

Permeability describes how easily water can flow through the rock or unconsolidated sediment and how easy it will be to extract the water for our purposes.

From Textbooks • Jan. 1, 2015

Permeability is the most important variable in groundwater.

From Textbooks • Jan. 1, 2015

The Porosity and Permeability of Bodies.—Take two tumblers of the same size, place one of them upon a table, and pour into it a small quantity of nearly boiling water.

From Scientific American Supplement, No. 492, June 6, 1885 by Various