ἀερόμυθος
From LSJ
Ἃ δέ σοι συνεχῶς παρήγγελλον, ταῦτα καὶ πρᾶττε καὶ μελέτα, στοιχεῖα τοῦ καλῶς ζῆν ταῦτ' εἶναι διαλαμβάνων (Epicurus, Letter to Menoeceus 123.2) → Carry on and practice the things I incessantly used to urge you to do, realizing that they are the essentials of a good life.
Greek (Liddell-Scott)
ἀερόμυθος: -ον, ὁ μάταια φλυαρῶν, ὁ λέγων λόγους τοῦ ἀέρος, Φίλων ΙΙ, 268, 46.
Spanish (DGE)
-ον charlatán Ph.2.268.