Definition of: cave

(kāv) noun
1. A natural cavity beneath the earth's surface or in a mountain; a cavern; den. ◆ Collateral adjective: spelean.
2. In English politics, a member of a party which seceded from the Liberals in 1866: so called from the application by John Bright of the expression Cave of Adullam (I Sam. xxii 1, 2) in referring to this party; hence, a seceder or a seceding group. See synonyms under HOLE.
—v. caved, cav·ing v.t.
1. To hollow out.
2. To cause to fall down or in, or to become hollow by a partial falling away.
3. To place in or as in a cave.
—v.i.
4. To fall in or down; give way, as ground when undermined.
—to cave in
1. To fall in or down, as when undermined; cause to fall in, as by undermining.
2. Colloq. To yield utterly; give in, as to argument, hardship, or strain. [<OF <L cava <cavus hollow]