noun. A natural depression in a land surface communicating with a subterranean passage, generally occurring in limestone regions and formed by solution or by collapse of a cavern roof.

noun. A hole formed in soluble rock by the action of water, serving to conduct surface water to an underground passage

noun. A depressed area in which waste or drainage collects.

noun. A hole in the playfield that rewards the player when the ball is guided into it.

noun. a depression in the ground communicating with a subterranean passage (especially in limestone) and formed by solution or by collapse of a cavern roof

"A sinkhole is a natural depression caused by the removal of soil by water."

depression  natural depression  

amphitheater  bayou  caldera  directa  escarpment  

cenote  dolina  doline  shakehole  sink