cavityn.[L. cavus hollow: cf. F. cavit.]1. Hollowness.()The cavity or hollowness of the place. (Goodwin.)2. A hollow place; a hollow; as, the abdominal cavity.()An instrument with a small cavity, like a small spoon (Arbuthnot.)Abnormal spaces or excavations are frequently formed in the lungs, which are designated cavities or vomic. (Quain.)Body cavity, the clum. See under Body.()