ἀτονία
From LSJ
ἡ γὰρ σιωπὴ τοῖς σοφοῖσιν ἀπόκρισις → silence, you see, is an answer for the wise (Menander)
English (LSJ)
ἡ,
A slackness, enervation, debility, Hp.Aër.20; laziness, Epicur.Nat.54 G.; ψυχῆς Plu.2.535d; ἀσθένεια καὶ ἀ. Luc.Nigr.36; ἰνῶν ἀ. καὶ τρόμος Phld.Acad.Ind.p.76M.; as Stoic term, lack of τόνος (q.v.), Chrysipp.Stoic.3.120,123, Arr.Epict. 2.15.4, etc.; in oratory, lack of vigour in delivery, Hermog.Inv.4.
German (Pape)
[Seite 387] ἡ, Abspannung, Mattigkeit, Plut. de vit. pud. 18; = ἀσθένεια Luc. Nigr. 36.
Greek (Liddell-Scott)
ἀτονία: ἡ, ἔκλυσις, χαλάρωσις τῶν δυνάμεων, ἀδυναμία, Ἱππ. π. Ἀέρ. 292, Πλούτ. 2. 535D.