Permeability, permeable, and semipermeable may refer to:

Chemistry

• Drug permeability

• Semipermeable membrane, a membrane which will allow certain molecules or ions to pass through it by diffusion

• Vascular permeability, the movement of fluids and molecules between the vascular and extravascular compartments

• Permeation of a gas or vapor through a solid substance

Earth and soil science

Permeability (earth sciences), a measure of the ability of a material (such as rocks) to transmit fluids

• Relative permeability, in multiphase flow in porous media

• Permeability (foundry sand), a test of the venting characteristics of a rammed foundry sand

Permeability of soils

• Hydraulic conductivity, the permeability of soil for water

Electromagnetism

Permeability (electromagnetism), the degree of magnetization of a material in response to a magnetic field

• Vacuum permeability, permeability of free space or magnetic constant, a physical constant, the value of magnetic permeability in a classical vacuum

Vehicles and transport

• Permeability (nautical), in ship design, the percentage of empty space in a compartment or tank

• Permeability (spatial and transport planning), the extent to which the layout of urban forms enables people or vehicles to move in different directions

Other uses

• Air permeability, characteristic of textile fabrics, measuring the ease of passage of air through them

• "Impermeable" (song), a song by Ha*Ash

• Permeable Press, an American publishing company