Meaning & use
permeability
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Meanings
noununcountablephysics
How easily a liquid or gas can pass through a material, such as rock, soil, or a cell wall.
Grammar: Often followed by of or to: the permeability of soil to water.
Patterns
- the permeability of something
- permeability to something
Sandy soil has high permeability, so water drains quickly.
The permeability of the membrane controls what enters the cell.
Engineers tested the rock's permeability before drilling.
noununcountablephysics
A measure of how easily a material lets a magnetic field pass through it.
Grammar: Used in physics: magnetic permeability.
Patterns
- magnetic permeability
Iron has a high magnetic permeability.
The transformer core was chosen for its permeability.
Magnetic permeability is measured in henries per meter.
Common combinations
- low permeability
- Clay has low permeability, so puddles stay for days.
- high permeability
- A sponge has high permeability to water.
- membrane permeability
- Membrane permeability changes when the cell is damaged.
- measure permeability
- Geologists measure permeability to predict water flow.
- permeability to
- The skin's permeability to chemicals varies.
Synonyms and how they differ
- porosity
- Porosity measures how much empty space a material has, while permeability measures how well fluids can flow through it.
- absorbency
- Absorbency describes soaking up liquid, which is not the same as letting it pass through.
- penetrability
- Penetrability is a rarer word that stresses being pierced, whereas permeability stresses seeping through pores.
Opposites
Word family
- permeable adjective
- allowing liquids or gases to pass through
- impermeable adjective
- not allowing liquids to pass through
- permeate verb
- to spread through every part of something
- semipermeable adjective
- letting only some substances pass
Commonly confused: permeability or porosity?
permeability vs porosity
A rock can be porous with many tiny holes yet still have low permeability if the holes do not connect.
Practice
A rock full of tiny holes that are not connected will have high porosity but low ______.
Choose one answer.
Permeability depends on whether fluid can flow through, and unconnected holes block flow. The other qualities are unaffected by connections between holes.
Make it your own
Write a sentence using “permeability”, then check it and compare it with the examples above.