Main Entry: sink·hole

Pronunciation: \ˈsiŋk-ˌhōl\

Function: noun

Date: 15th century

1 : a hollow place or depression in which drainage collects
2 : a hollow in a limestone region that communicates with a cavern or passage
3 : sink 2
4 : something (as an unprofitable investment) that steadily drains money or resources <a financial sinkhole>