| fail(verb, stop, end, decline, pass) |
| get worse(expression, decline, weaken, lessen, degenerate) |
| go off(verb, expression, phrasal verb, spoil, deterioration) |
| go to the dogs(expression, idiom, decline, weaken, lessen) |
| hit rock bottom(expression, idiom, decline, weaken, lessen) |
| hit the skids(expression, idiom, decline, weaken, lessen) |
| lessen(verb, decline, weaken, degenerate, deteriorate) |
| pejorate(decline, weaken, lessen, degenerate, deteriorate) |
| pollute(verb, decline, weaken, lessen, degenerate) |
| reach depths(expression, decline, weaken, lessen, degenerate) |
| sap(decline, weaken, lessen, degenerate, deteriorate) |
| shrivel(decline, weaken, lessen, degenerate, deteriorate) |
| sicken(decline, weaken, lessen, degenerate, deteriorate) |
| sink(verb, stop, break, end, decline) |
| slump(decline, weaken, lessen, degenerate, deteriorate) |
| weaken(verb, stop, end, decline, pass) |
| go moldy(expression, idiom, decay, decompose) |
| grow moldy(expression, idiom, decompose) |
| become tainted(verb, expression, decay, taint) |
| become useless(verb, expression, decay, taint) |