窿 Strokes Write it Listen 窿 lóng mine shaft; cavity, hole HSK 7–9 16 strokes Radical 穴 Sound + meaning 1 word Built from穴meaningxuécave, den, hole隆soundlóngprosperous, plentiful, abundant How it works穴 hints at the meaning (hole), and 隆 lóng hints at the sound.