sinkhole Synonyms

swallow hole sink deepest valley borehole caldera aquifer yama water table water level void artesian spring bottomless pit cenote collapsing hole artesian basin sinks sinkage hellhole Dells chughole chuckhole cesspit trough indentation sinking culvert crater concavity cesspool cavity bowl bottomless blowhole bay decline dent scoop SAG pit hollow hole doghole ditch dip depression basin