| exacerbate(verb, degenerate, degrade, worsen) |
| hit the skids(verb, expression, idiom, drop, strong) |
| pervert(verb, change, decline, hurt, reduce) |
| shrivel(verb, drop, cut, decline, reduce) |
| slacken(verb, stop, drop, cut, decline) |
| turn(verb, decline, return, weaken, lessen) |
| undermine(verb, decline, fail, damage, harm) |
| damage(verb, hurt, reduce, destroy, lower) |
| abase(verb, reduce, destroy, damage, diminish) |
| adulterate(verb, cut, decline, ruin, fail) |
| become rotten |
| become worse(verb, expression, idiom, decline, weaken) |
| break down(verb, expression, phrasal verb, stop, break) |
| come down(verb, worsen) |
| contaminate(cut, hurt, thin, spoil, corrupt) |
| discolor(verb, decline, weaken, lessen, degenerate) |
| disimprove(verb, drop, decline, reduce, fall) |
| downgrade(verb, reduce, destroy, damage, diminish) |
| fatigue(verb, decline, diminish, use, weary) |
| fizzle(verb, phrasal verb, strong, decline, increase) |