sinkhole.

A depression or opening formed when the ground subsides or collapses, often above an underground cavity.

Use it for

Words that belong together

• a widening sinkhole
• limestone sinkhole

On the page

A sinkhole opened beside the old track.

Water gathered in the sinkhole beneath the leaning trees.

Usage notes

Primary category: environment. Forms: Singular sinkhole; plural sinkholes. Legacy lexical fields mirror sense 1 only. Use numbered sense fields for all meanings.