What does compressible mean?
Compressible is an adjective describing something that can be pressed into a smaller volume — in other words, made to occupy less space through the application of pressure. The word belongs chiefly to the vocabulary of physics and engineering: gases such as air are notably compressible because their molecules can be pushed closer together, while liquids and solids like water are nearly incompressible, resisting any significant reduction in volume. This distinction matters enormously in practice, shaping everything from pneumatic tools and refrigeration systems to aerodynamic calculations, where engineers must decide whether to treat airflow as compressible or not. By extension, the word can be used figuratively for anything — a schedule, an essay, a budget — that can readily be condensed or cut down. Its natural opposite is incompressible, and its abstract noun form, compressibility, names the degree to which a substance yields to pressure.
adjectiveCapable of being compressed, especially capable of being reduced in volume by pressure. In physics, describes a substance (typically a gas) whose volume decreases under applied pressure.
- (of a substance, especially a gas) capable of being reduced in volume by pressure
- (figurative) able to be condensed, shortened, or reduced in size or extent
"Unlike liquids, gases are highly compressible, which is why they are used to store energy in pneumatic systems."
"Because air is compressible, it can absorb shocks in a car's suspension system."
"The editor found the draft highly compressible and cut it from forty pages to twelve."
Every breath you take works because air is compressible — but squeeze water as hard as you like and it barely budges.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of compressible
Compressible derives from the Latin verb comprimere, meaning 'to press together', formed from com- ('together') plus premere ('to press'). The word entered English in the early 17th century, during the period when Latin-derived scientific terminology was being widely absorbed into the language. It shares this root with related English words such as compression, compressor, depress, and suppress, all built on the same Latin stem premere.
Related word forms
How compressible is actually used
A technical term most common in physics and engineering contexts, particularly fluid dynamics, where 'compressible flow' contrasts with 'incompressible' treatments of fluids. The figurative sense is rarer and informal.
Easily confused with compressible
'Compressible' means able to be squeezed into less space, while 'comprehensive' means covering all or nearly all elements or aspects of something.
'Compressible' refers to physical reducibility under pressure, whereas 'comprehensible' means capable of being understood.