1. An error usually caused by forgetfulness: “The severe accident seems to be the cause of her lapse of memory.”
2. The termination of protection or coverage in an insurance policy due to lack of payment: “My membership of the life insurance policy may lapse for not paying the annual subscription.”
3. To subside or to sink away gradually from a typical pattern of belief or behavior: “The shock of the death of his mother lapsed him into silence.”
Elapse means a passage or gap in time between events: “Though many years of ceasefire have elapsed, yet India and China do not have normal and peaceful political relations.”
Relapse means a backsliding, recurrence, or worsening: ” The doctor has advised me to take caution otherwise my illness may relapse causing serious complications.”