μελύδριον
From LSJ
τὸ ἀγαθὸν αἱρετόν· τὸ δ' αἱρετὸν ἀρεστόν· τὸ δ' ἀρεστὸν ἐπαινετόν· τὸ δ' ἐπαινετὸν καλόν → what is good is chosen, what is chosen is approved, what is approved is admired, what is admired is beautiful
English (LSJ)
τό, Dim. of μέλος A,
A poor limb, M.Ant.7.68(pl.). II Dim. of μέλος B, ditty, Ar.Ec.883, Theoc.7.51, BionFr.5.1.