What does compressional mean?
Compressional is an adjective meaning relating to compression, the process by which material is squeezed, shortened, or made more compact. Its most familiar technical use is in seismology, where a compressional wave is a longitudinal wave that travels through Earth by alternately compressing and expanding the material. Such waves are commonly called P waves and generally arrive before the slower shear waves. In mechanics and geology, the adjective can also describe stresses, strains, or deformations caused by compression. The term is not interchangeable with “compressed,” which describes material that has already undergone the process, nor is it usually the most natural choice in ordinary speech. “Compressive” is often preferable when describing a force or effect that produces compression. Compressional is nevertheless useful in scientific writing because it identifies phenomena associated with compression precisely, particularly the behavior and movement of longitudinal waves through solids.
adjectiveRelating to compression, especially to the shortening or squeezing of material or to waves that create compression. In seismology, it designates a longitudinal wave in which particles vibrate in the direction of wave propagation.
- Relating to compression or to the shortening, squeezing, or increased density of material; especially used for longitudinal seismic waves.
"The compressional wave reached the monitoring station several seconds before the shear wave."
"The compressional wave reached the monitoring station several seconds before the shear wave."
"Laboratory tests revealed substantial compressional strain in the layered material."
When an earthquake arrives, its compressional wave is the first seismic signal to race through the ground.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does compressional come from?
Compressional was formed in English from compression, which came through French from Latin compressio, a noun derived from comprimere, meaning “to press together.” Latin comprimere combines the intensive prefix com- with premere, “to press.” The same root underlies related English words such as compress, compressor, and compressible.
How compressional is actually used
This is chiefly a technical term used in physics, mechanics, geology, and seismology. In general prose, “compressive” is often more idiomatic for describing something that applies compression, while “compressional” is especially associated with seismic waves.
Easily confused with compressional
Compressional means relating to compression, especially a wave or other physical effect, whereas compressive means tending to compress or undergoing compression.