permeability

Etymology

It is formed from English permeable + -ity,^[2][3][4][5] perhaps also after French perméabilité, recorded in French from 1755.^[3][2] Permeable, recorded from about 1439, is from Late Latin permeābilis (“that can be passed through”), from permeō (“to pass through”),^[2][3] formed from per (“through”) and meō (“to pass”).^[3]

Earliest recorded meaning

The quality of being permeable, especially the degree to which a solid lets liquids or gases pass through it: 1760, in the Philosophical Transactions of the Royal Society for 1759.^[2][6] The 1989 edition of the OED dated it 1759, from the year of that volume,^[7] and Etymonline gives 1733.^[3]

Semantic evolution

The word followed the scientific sense of permeable, capable of being permeated, which is recorded from 1773.^[2][3] In 1872 W. Thomson used permeability in physics for a property of a medium in a magnetic field, the ratio of the magnetic induction to the field strength, now usually called magnetic permeability.^[2][4] A measured coefficient of permeability, the volume of fluid flowing through a unit cross-section in unit time, followed in 1917 in aeronautics and soil science,^[2] and radio engineers spoke of permeability tuning from 1933.^[7]

Timeline

• 1760 – the quality of being permeable; the degree to which a solid lets fluids pass.^[2][6]
• 1872 – in physics, magnetic permeability.^[2]
• 1917 – coefficient of permeability, a measured rate of flow.^[2]
• 1933 – permeability tuning, in electronics.^[7]

Meanings

Noun

1. The quality or state of being permeable: the permeability of the cell wall.^[6][8][9]
2. The rate at which a liquid or gas flows through a porous material such as soil or rock.^[8][6][9]
3. (physics) The ratio of the magnetic flux density in a medium to the strength of the magnetic field causing it, measured in henries per metre; also called magnetic permeability.^[9][4][2]
4. The rate at which a gas diffuses through a surface.^[9]

Word family

• magnetic permeability

Related words

• impermeable
• nonpermeable
• permeameter
• permeable
• permeate

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
5. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
6. ^ a b c d Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
7. ^ a b c Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press
8. ^ a b The American Heritage Dictionary of the English Language (1992), 3rd ed., Boston: Houghton Mifflin
9. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins