What does incompressible mean?
Incompressible is an adjective describing something that cannot be compressed, especially a material or fluid whose volume does not appreciably decrease when pressure is applied. In scientific and engineering contexts, it is used when calculating or describing how substances respond to force, such as for liquids, solids, and layered geological formations. The word can also be used figuratively to describe a person, principle, or position that resists pressure, persuasion, or alteration. Its familiar related noun is incompressibility, which names the property of resisting compression, and the adverb incompressibly expresses an action done in an unyielding or immovable way. Although the word is most common in technical writing, its figurative use can be effective for emphasizing strength, rigidity, or an unwillingness to compromise.
adjectiveUnable to be compressed or reduced in volume under pressure. In figurative use, unable to be persuaded, constrained, or diminished.
- Unable to be compressed or reduced in volume under pressure.
- Figuratively, unable to be persuaded, constrained, or diminished.
"The incompressible fluid maintained a nearly constant volume as pressure increased."
"Water is treated as essentially incompressible in many engineering calculations."
"Her principles remained incompressible despite pressure from her colleagues."
Some materials can be squeezed without losing much volume; incompressible ones resist compression and make ideal subjects for studying the behavior of fluids under pressure.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does incompressible come from?
The word comes from the Latin prefix in- meaning 'not' and the Latin verb comprimere, meaning 'to press' or 'squeeze.' The related English word compress developed from the same Latin root, while compression and decompress are later formations built on that shared root. Incompressible entered English in the 17th century in the sense of something unable to be pressed or squeezed.
Related word forms
How incompressible is actually used
The physical sense is chiefly technical, especially in physics, engineering, and materials science. The figurative sense is less common and usually implies firmness, resistance, or an unwillingness to yield.
Easily confused with incompressible
Incompressible describes something that cannot be compressed or reduced in volume, whereas incurable describes a disease or condition that cannot be cured.