What does cavitation mean?
Cavitation is the formation of vapor-filled bubbles within a liquid, occurring when local pressure drops below the liquid's vapor pressure — most commonly around fast-spinning ship propellers, pump impellers, or in ultrasonic devices. The phenomenon matters because these bubbles do not merely vanish: when they encounter higher pressure they collapse violently, generating microscopic shock waves intense enough to pit and erode hardened steel over time, a problem engineers call cavitation damage. The same destructive energy is harnessed productively in ultrasonic cleaning, medical lithotripsy, and sonochemistry. In medicine and dentistry, cavitation has a second sense: the formation of a hollow space within tissue, as in a lesion or surgical site. A technical term rather than everyday vocabulary, cavitation appears mainly in engineering, physics, and clinical literature, and it derives from the Latin 'cavus', meaning hollow — the same root that gives us 'cavity' and 'excavate'.
The formation of vapor-filled cavities in a liquid when pressure drops below vapor pressure, whose collapse produces shock waves capable of eroding nearby surfaces.
"Cavitation on the propeller blades reduced the vessel's speed and eventually ate holes in the metal."
Most common in engineering and physics contexts.
The formation of a cavity or hollow space in body tissue, as in a lesion or abscess.
"Imaging showed cavitation within the lung nodule, suggesting necrosis."
The plural is used when referring to multiple distinct instances of bubble formation or multiple cavities in tissue, though the mass-noun singular is more common for the general phenomenon.
"The ultrasound scan revealed several small cavitations along the damaged valve surface."
Cavitation is so powerful that collapsing steam bubbles can punch holes through steel propellers — and pistol shrimp use it to stun prey with a snap hotter than the sun's surface.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cavitation
Cavitation comes from the Latin 'cavus', meaning 'hollow', via the Late Latin noun 'cavitas' ('hollowness'), which passed into English as 'cavity'. The term arose in the late nineteenth century, when engineers investigating unexplained erosion and loss of efficiency in ship propellers identified the formation and collapse of vapor bubbles as the cause. It shares this root with cognates such as 'cavity', 'excavate', and 'concave', all pointing to the underlying idea of hollowness.
Related word forms
How cavitation is actually used
Cavitation is a technical term used chiefly in fluid dynamics, engineering, ultrasonics, and medical contexts. It carries no emotional connotation but often implies unwanted damage when discussed in engineering, since bubble collapse can destroy equipment. In dentistry and medicine it refers to cavity formation in tissue. The verb form 'cavitate' is common in medical writing.
Easily confused with cavitation
A cavity is the hollow space itself (as in a tooth), whereas cavitation is the process of forming bubbles in a liquid or cavities in material.
Evaporation is a gradual surface change from liquid to gas driven by heat, while cavitation is the rapid formation of vapor bubbles caused by low pressure within the bulk of the liquid.