| degenerate(verb, drop, strong, decline, increase) |
| depreciate(verb, drop, decline, fall, fail) |
| die |
| discolor(verb, decline, weaken, lessen, degenerate) |
| dissolve(verb, decline, weaken, lessen, degenerate) |
| droop(verb, drop, fall, fail, diminish) |
| drop(verb, fall, fail, return, lower) |
| dry-rot(verb, decline, weaken, lessen, degenerate) |
| dwindle(verb, drop, decline, fall, fail) |
| ebb(verb, drop, decline, fall, fail) |
| fall flat(verb, expression, decline, fall, fail) |
| fall off(verb, expression, phrasal verb, drop, fall) |
| fall short(verb, expression, decline, fall, fail) |
| fall through(verb, expression, phrasal verb, decline, fall) |
| fizzle(verb, strong, decline, increase, fall) |
| flop(verb, decline, fall, fail, slip) |
| flounder(verb, decline, fall, fail, slip) |
| fold(verb, decline, fall, fail, slip) |
| founder(verb, decline, fall, fail, slip) |
| get worse(verb, expression, decline, weaken, lessen) |