a sink (in various senses) that receives or contains water; esp. a swallow hole or sinkhole (sinkhole, n. 2).

spec. An opening or cavity, such as are common in limestone formations, through which a stream disappears underground: also called swallow-pit, s…

= swallow, n.2 1b.

gen. A tidal opening, an inlet or creek through which the tide enters; an arm of the sea indenting the land. rare in modern use.

An underground stream of water such as breaks in upon miners at work. Also (in full, swallet hole), the opening through which a stream disappears…

In Jamaica: a rocky hollow or sinkhole enclosed by steep-sided forested hills. Cf. cockpit country n. cockpit karst n. at compounds 2.

A hole or depression in the ground formed as the result of erosion or collapse of underlying rock, soil, etc.; esp. a cavity resulting from…

A cavity in the ground into which surface water escapes, a swallow hole; esp. one resulting from dissolution of rock (typically limestone) by…

A natural deep hole or pit, esp. in limestone.

An opening or deep cavity in the ground through which a stream or river disappears underground, esp. in an area of water-soluble rock formations…

(see quots.).

A hole formed by the wearing away of rock by the rotation of stones in running water or by glacial erosion; (more generally) any cylindrical or deep…

(see quot.)

A natural opening in rocks or ice through which the sea spouts.

A subterranean channel or deep chasm formed by the action of water.

In a karstic region: a steep natural shaft which emerges at the surface of the ground, frequently as a swallow hole.

Caving and Diving. An underground passage or chamber in which water collects; esp. one that is flooded.