Synonyms for relapse

reversion, recidivism, backsliding, regression, recurrence, decline, deterioration, reverse, reversal, setback; see also decay 1, loss 3.

lapse, retrogress, fall, backslide, become a backslider, revert, regress, suffer a relapse, deteriorate, degenerate, retrovert, fall from grace, fall back, fall off, weaken, sink back, fall into again, slide back, slip back, be overcome, succumb, give in to again.