I. re ‧ lapse 1 /rɪˈlæps/ BrE AmE verb [intransitive]
1 . to become ill again after you have seemed to improve
relapse into
We were afraid he might relapse into a coma.
2 . to start to behave badly again
relapse into
Clara soon relapsed into her old ways.
II. re ‧ lapse 2 /rɪˈlæps $ ˈriːlæps/ BrE AmE noun [uncountable and countable]
[ Date: 1400-1500 ; Language: Latin ; Origin: past participle of relabi 'to slide back' ]
when someone becomes ill again after having seemed to improve:
She had a relapse and died soon after.