| dip(noun, drop, decline, fall, depression) |
| sag(noun, drop, decline, fall, sink) |
| basin(noun, drop, area, decline, fall) |
| decline(noun, drop, fall, plunge, slump) |
| depression(noun, drop, decline, fall, dish) |
| droop(noun, drop, decline, fall, plunge) |
| hollow(noun, drop, area, decline, fall) |
| sinking(noun, drop, decline, fall, plunge) |
| slump(noun, drop, decline, fall) |
| concavity(noun, drop, decline, fall, depression) |
| draft |
| excavation(noun, depression, impression, dip, hollow) |
| lowering(noun, slump, deflation, reducing) |
| sink(noun, drop, decline, fall, depression) |
| subsidence |
| bay(noun, dish, sink, pot, bowl) |
| bowl(noun, depression, dish, impression, sink) |
| catenary |
| cave-in(noun, drop, decline, fall, collapse) |
| cave in(noun, expression, drop, fall, plunge) |