| sap(verb, decline, weaken, lessen, degenerate) |
| shrivel(verb, decline, weaken, lessen, degenerate) |
| sicken(verb, decline, weaken, lessen, degenerate) |
| sink(verb, drop, decline, reduce, fall) |
| slump(verb, decline, weaken, lessen, degenerate) |
| spoil(verb, decline, fail, lower, weaken) |
| suppurate(verb, decline, weaken, lessen, degenerate) |
| turn(verb, decline, weaken, lessen, degenerate) |
| wane(verb, drop, decline, fall, fail) |
| waste away(verb, expression, phrasal verb, decline, weaken) |
| weaken(verb, drop, decline, fall, fail) |
| wear away(verb, expression, phrasal verb, decline, fail) |
| abate(verb, drop, fall, fail, diminish) |
| adulterate(verb, decline, weaken, degenerate, deteriorate) |
| alloy(verb, decline, weaken, degenerate, deteriorate) |
| atrophy(verb, decline, degenerate, deteriorate, better) |
| backslide(verb, drop, reduce, fall, fail) |
| be worse for wear(verb, decline, fail, lower, weaken) |
| become less(verb, expression, drop, fall, fail) |
| become worse(verb, expression, decline, fail, lower) |