From Longman Dictionary of Contemporary Englishmerciful death/end/releasemerciful death/end/releaseMXDIEa death or end to something that seems fortunate because it ends someone’s suffering SYN welcome I think my uncle’s death was a merciful release for my poor aunt. → merciful
Examples from the Corpus
merciful death/end/release• With the Giants leading 28-7, half-time came as a merciful relief.• And Elinor was just going to have to wait for her merciful release.• These were the alternatives to a quick, merciful death.• Those animals put down had a merciful release.• Death had been a merciful release for him. 