| putrefy(verb, decline, weaken, lessen, degenerate) |
| putresce(verb, decline, weaken, lessen, degenerate) |
| reach depths(verb, expression, decline, weaken, lessen) |
| regress(decline, weaken, worsen) |
| retrograde(verb, decline, diminish, weaken, degenerate) |
| retrogress(verb, decline, diminish, weaken, degenerate) |
| rot(verb, decline, weaken, lessen, degenerate) |
| sap(verb, decline, weaken, lessen, degenerate) |
| shrivel(verb, decline, weaken, lessen, degenerate) |
| slide(verb, decline, weaken, worsen) |
| slump(verb, decline, weaken, lessen, degenerate) |
| spoil(verb, decline, weaken, lessen, degenerate) |
| suppurate(verb, decline, weaken, lessen, degenerate) |
| turn(verb, decline, weaken, lessen, degenerate) |
| wane(verb, decline, weaken, lessen, degenerate) |
| waste away(verb, expression, phrasal verb, decline, weaken) |
| weaken(verb, decline, slip, degenerate, deteriorate) |
| wear away(verb, expression, phrasal verb, decline, weaken) |
| atrophy(verb, decline, degenerate, deteriorate, wane) |
| become rotten |