ma·nes \ˈmäˌnās, ˈmāˌnēz\noun plural Etymology: Latin; perhaps akin to Latin manus good — more at mature 1.often capitalized: the spirits of the dead and gods of the lower world in ancient Roman belief — compare lemures 2. a.: ancestral spirits worshiped as gods b.singular in construction: the spirit of a dead person regarded as an object to be venerated or appeased