窟

Kanji: 窟
Level: N1
Meaning: cavern, cave
On'yomi: クツ
Kun'yomi: いわや
Strokes: 13
Common compounds: 洞窟 (どうくつ) cave 地底窟 (ちていくつ) underground cave
Memory hook: A cave (窟) is a hole (穴) where you bend (屈) down.