ἀθόρυβος
From LSJ
ὕπνος δεινὸν ἀνθρώποις κακόν → sleep is a terrible evil for humans (Menander, Sententiae monostichoi 1.523)
English (LSJ)
ον,
A without uproar, Pl.Lg.640c; unperturbed, Polystr.p.29 W., prob. l. in Metrod.Fr.48 K. : Comp., Anon. in SE 15.19. Adv. -βως E.Or.630, Epicur.Fr.489, J.BJ2.12.6, Hierocl. in CA12p.447M. II not causing confusion, Ascl.Tact.12.10 (Comp.).
Greek (Liddell-Scott)
ἀθόρυβος: -ον, ἄνευ θορύβου, ἀτάραχος, ἥσυχος, Πλάτ. Νόμ. 640C. ― Ἐπίρρ. -βως, Εὐρ. Ὀρ. 630.