noun
plural -lapses
the return of an illness after a period of improvement [count]
a return to bad behavior that you had stopped doing [count]
verb
-lapses; -lapsed; -lapsing
[no obj]
to become ill again after a period of improvement in health
b of an illness :to return or become worse after leaving or improving for a period of time
to return to a bad condition, form of behavior, etc.