mercy killing mercy • mercyproof · · · Info · Definitions · Synonyms · Characters · · mercy killing · · Text Common · · Latin · · Scripts 13 · · Length 4 · · Syllables Definitions · · · (noun) the act of killing someone painlessly (especially someone suffering from an incurable illness). Synonyms: euthanasia, mercy killing. · · Noun Definition 1 Synonyms · · · euthanasia · · Synonym 1 Characters · · space U+0020 c latin small letter c U+0063 e latin small letter e U+0065 g latin small letter g U+0067 i latin small letter i U+0069 k latin small letter k U+006B l latin small letter l U+006C m latin small letter m U+006D n latin small letter n U+006E r latin small letter r U+0072 y latin small letter y U+0079