| cave-in(drop, decline, fall, plunge, slide) |
| coast(drop, decline, fall, plunge, slide) |
| crash(drop, decline, fall, plunge, slide) |
| declension(drop, decline, fall, plunge, slide) |
| declination(drop, decline, fall, plunge, slide) |
| decline(drop, fall, plunge, slide, dive) |
| declivity(drop, fall, plunge, slide, dive) |
| descent(noun, down, lowering) |
| downgrade(drop, decline, fall, plunge, slide) |
| droop(drop, decline, fall, plunge, slide) |
| drop-off(drop, decline, fall, plunge, slide) |
| fall(drop, decline, plunge, slide, dive) |
| falling(drop, decline, fall, plunge, slide) |
| grade(drop, decline, fall, plunge, slide) |
| gradient(drop, decline, fall, plunge, slide) |
| header(drop, decline, fall, plunge, slide) |
| hill(drop, fall, plunge, slide, dive) |
| inclination(drop, decline, fall, plunge, slide) |
| incline(drop, fall, plunge, slide, dive) |
| landslide(drop, decline, fall, plunge, slide) |