(Ἐπαινή), that is, the fearful, a surname of Persephone. (Hom. Il. 9.457.) Plutarch (de Aud poet. p. 23a.) derives the name from αἶνος, which suggests, that it might also be understood in a euphemistic sense as the praised goddess.
[L.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890