relapse

RELAPSE noun

[ C,U ] uk/rɪˈlæps, ˈriːlæps/ us relapse noun [C, U]
(WORSE)

an occasion when something or someone gets worse again after being better

повторное ухудшение
The company's share prices have suffered a relapse this week. relapse verb [ I ] uk/rɪˈlæps/ us

вновь заболевать, ухудшаться