a mountain cave.

A natural subterranean cavern or (less commonly) fissure.

A natural cave in which the temperature remains cool (and which may contain ice) throughout the year.

(the name of) a cave in which many bones (typically hundreds or thousands of years old) have been found.

U.S. regional (southern and south Midland). A shelter beneath overhanging rocks, esp. one that provides a suitable habitat for ferns.

A miniature cave.