| be overtaken(fall, fail, weaken, degenerate, deteriorate) |
| fade(fall, fail, collapse, weaken, degenerate) |
| fail(fall, collapse, weaken, degenerate, deteriorate) |
| faint(verb, collapse, lose, succumb) |
| fall(fail, collapse, weaken, degenerate, deteriorate) |
| fall back(expression, fall, fail, degenerate, deteriorate) |
| lapse(fall, fail, degenerate, deteriorate, revert) |
| recidivate(fall, fail, weaken, degenerate, deteriorate) |
| regress(fall, fail, weaken, degenerate, deteriorate) |
| relapse(verb, weaken, degenerate, deteriorate, revert) |
| retrogress(fall, fail, degenerate, deteriorate, revert) |
| sicken(fall, fail, weaken, degenerate, deteriorate) |
| sink(fall, fail, degenerate, deteriorate, revert) |
| slide back(expression, fall, fail, weaken, degenerate) |
| slip back(expression, fall, fail, weaken, degenerate) |
| succumb |
| suffer(fall, fail, weaken, degenerate, deteriorate) |
| swoon(verb, collapse, faint, succumb) |
| turn back(expression, fall, fail, weaken, degenerate) |
| weaken(verb, drop, fall, collapse, lapse) |