noun · a figurative hideout or den for criminals and thieves

官兵搜查了那处被当作狗窦的废弃宅院。

noun · an opening in a wall or fence for a dog to pass through

墙角下有一个供小狗进出的狗窦。

a gap in the mouth caused by missing teeth

他掉了一颗门牙，一笑就露出了个狗窦。