Manes (pl.) Look up Manes at Dictionary.com
"Gods of the Lower World," in Roman religion, from Latin manes "departed spirit, ghost, shade of the dead, deified spirits of the underworld," usually said to be related to Latin manus "good," thus properly "the good gods," a euphemistic word. De Vaan cites cognates Old Irish maith, Welsh mad, Breton mat "good." Ultimate etymology uncertain.