| deteriorate(verb, drop, decline, fall, fail) |
| decline(verb, fail, lower, weaken, lessen) |
| worsen(verb, drop, decline, fall, fail) |
| degenerate(verb, drop, decline, fall, fail) |
| go to the dogs(verb, expression, idiom, drop, decline) |
| decay(verb, drop, decline, fall, fail) |
| go downhill(verb, expression, drop, decline, fall) |
| sink(verb, drop, decline, fall, fail) |
| break(verb, decline, fail, lower, weaken) |
| disimprove(verb, drop, decline, fall, fail) |
| fail(verb, drop, decline, fall, diminish) |
| go to seed(verb, expression, idiom, fail, weaken) |
| rot(verb, drop, decline, fall, fail) |
| seed |
| slip |
| spoil(verb, decline, fail, lower, weaken) |
| abate(verb, drop, fall, fail, diminish) |
| adulterate(verb, decline, weaken, degenerate, deteriorate) |
| alloy(verb, decline, weaken, degenerate, deteriorate) |
| backslide(verb, drop, fall, fail, diminish) |