Английский Этимологический словарь - funeral (n.)

- 1437, from M.Fr. funйrailles (pl.) "funeral rites," from M.L. funeralia "funeral rites," originally neut. pl. of L.L. funeralis "having to do with a funeral," from L. funus (gen. funeris) "funeral, death, corpse," origin unknown. Singular and plural used interchangably until c.1700. The adj. funereal is first attested 1725, by influence of M.Fr. funerail, from L. funereus, from funus.