lap-tóo塌堵

to sink inward or downward

to sink inward or downward; to form a depression (slab, wall, etc.)

English Wiktionary, “塌堵” (CC BY-SA 4.0) — https://en.wiktionary.org/wiki/%E5%A1%8C%E5%A0%B5 · confidence: High (Wiktionary, PH/Quanzhou/Jinjiang)