ἐναντιότης
From LSJ
νόσημα γὰρ αἴσχιστον εἶναί φημι συνθέτους λόγους → for I consider false words to be the foulest sickness
English (LSJ)
ητος, ἡ,
A contrariety, opposition, Pl.Phd.105a, A.D.Conj. 253.16, Ph.1.7, etc.; πρὸς ἀλλήλω Pl.Tht.186b, etc.: pl., Ocell.2.4. II in the Philos. of Arist., contrariety, Int.21a29, EN1108b27; v. ἐναντίος 1.4.