relapse verb definition in Being ill topic from the Oxford Advanced Learner's Dictionary

relapse

 verb: Being ill topic
BrE /rɪˈlæps/ ; NAmE /rɪˈlæps/ [intransitive] relapse (into something) to go back into a previous condition or into a worse state after making an improvement They relapsed into silence. He relapsed into his old bad habits. Two days after leaving the hospital she relapsed into a coma.