sinkhole
n.a large hole in the ground that suddenly appears. It is usually caused by water washing away the soil or rock underneath the surface.
n.a depression or hole in the ground surface, typically caused by the collapse of the surface layer or the dissolution of underlying soluble rock.
“A large sinkhole opened up in the middle of the street.”
“Heavy rains over several weeks weakened the limestone bedrock, eventually causing a massive sinkhole to swallow the old farmhouse.”
“Geologists monitor the region for signs of subsidence, as the porous limestone is highly susceptible to the formation of a sinkhole following a prolonged period of drought followed by intense rainfall.”
“G rief is a sinkhole, opening up where real life once stood.”
“Walker and her colleagues collected historical animal bones from Green Waterhole and Gouldens Sinkhole, two underwater cave systems near Mount Gambier, South Australia.”
From Middle English sinkehole, sinkeholl, equivalent to sink + hole.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.