cavitation (n.)

"a hollow place, empty space in the body," 1540s, from French cavité (13c.), from Late Latin cavitatem (nominative cavitas) "hollowness," from Latin cavus "hollow" (from PIE root *keue- "to swell," also "vault, hole").

the end of some nouns of action; see -ate + -ion.

"to form cavities or bubbles (in a fluid)," 1892 (implied in cavitated), back-formation from cavitation or else formed from cavity + -ate (2) . Related: Cavitating.