Search Result for "sinkhole": 
Wordnet 3.0

NOUN (1)

1. a depression in the ground communicating with a subterranean passage (especially in limestone) and formed by solution or by collapse of a cavern roof;
[syn: sinkhole, sink, swallow hole]


WordNet (r) 3.0 (2006):

sinkhole n 1: a depression in the ground communicating with a subterranean passage (especially in limestone) and formed by solution or by collapse of a cavern roof [syn: sinkhole, sink, swallow hole]