Real Dictionary

cavitation in American English
the formation of partial vacuums within a flowing liquid as a result of mechanical force, as with a boat propeller or a pump impeller: when these collapse, pitting or other damage is caused on metal surfaces in contact
noun: the rapid formation and collapse of vapor pockets in a flowing liquid in regions of very low pressure, a frequent cause of structural damage to propellers, pumps, etc

cavitation in British English
noun: the formation of vapour- or gas-filled cavities in a flowing liquid when tensile stress is superimposed on the ambient pressure

cavitation in Chemical Engineering
noun: Cavitation is when vapor bubbles form in a flowing fluid because of a sudden decrease in pressure.