sinkhole
noun [ C ] uk/ˈsɪŋk.həʊl/ us/ˈsɪŋk.hoʊl/
(HOLE)
（尤指在石灰岩地面由于雨水冲刷而自然形成的）灰岩坑，天坑
a hole in the ground, especially in an area of limestone rock, that has been formed naturally, for example by water that has worn away the rock
Rain gradually dissolves the limestone, forming features such as limestone pavements, sinkholes, and caves. 雨水会逐渐溶解石灰岩，形成灰岩喀斯特面、灰岩坑、溶洞等特征。
Compare: abyss (HOLE) canyonchasmcleftcrater nouncrevassedefile noun gorge noun (VALLEY)gulf (AREA) gullyravinerift
天坑（指地表不受支撑时突然出现在地面上的一个大洞）
a large hole that suddenly appears in the ground when the surface of the ground is no longer supported
A massive sinkhole has opened over old potash mines in the area. 这个地区的老钾矿突然出现了一个巨大的天坑。
A man was missing early Friday after a large sinkhole opened under the bedroom of his house in Florida. 周五早些时候，佛罗里达州一名男子的卧室地面突然出现了一个巨大的天坑，他随后失踪。