| 窟 | いわや | cavern; grotto |
| アヘン窟 | あへんくつ | opium den |
| 屁理窟 | へりくつ | sophism; chop logic; far-fetched argument; quibble; cavil; argument for argument's sake |
| 窟 | やぐら | caves dug as tombs in and around Kamakura during the Kamakura and Muromachi periods |
| 洞窟熊 | ほらあなぐま | cave bear (extinct, Ursus spelaeus) |