ἀυδρία
Τὸ νικᾶν αὐτὸν αὑτὸν πασῶν νικῶν πρώτη τε καὶ ἀρίστη. Τὸ δὲ ἡττᾶσθαι αὐτὸν ὑφ' ἑαυτοῦ πάντων αἴσχιστόν τε ἅμα καὶ κάκιστον. → Τo conquer yourself is the first and best victory of all, while to be conquered by yourself is of all the most shameful as well as evil
English (LSJ)
ἡ, A = ἀνυδρία, Pl.Lg.844a, Thphr.HP8.6.6.
German (Pape)
[Seite 391] ἡ, = ἀνυδρία, v. l. Plat. Legg. VIII, 844 a. S. Lob. Phryn. 729.
Greek (Liddell-Scott)
ἀϋδρία: ἡ, = ἀνυδρία, Πλάτ. Νόμ. 844Α, Βεκκ.
Spanish (DGE)
-ας, ἡ
sequía, aridez τισι τόποις σύμφυτος Pl.Lg.844a, χώρας Thphr.HP 8.6.6, BE 1976.267 (Esparta III a.C.?); cf. ἀνυδρία.
Greek Monolingual
Russian (Dvoretsky)
ἀϋδρία: ἡ Plat. v. l. = ἀνυδρία.
ἀϋδρία/ἀυδρία
ἀϋδρία or ἀυδρία? And there's the additional complication of those ancient (usually late) authors who spell it (properly, they thought) with the movable nu, since the alpha privative occurs before a vowel (ἀνυδρία, "lack of water"). As for ἀυδρία vs. ἀϋδρία, Plato manuscripts show the former, Theophrastus manuscripts (Historia plantarum 8.6.5.2) the latter. Plato and Theophrastus had no diaeresis-sign, and no need for it, so it's really a question of taste for medieval scribes. My preference would be for the most simple: ἀυδρία.
Additional observation: the disappearance in late antiquity of the initial rough breathing (dasia) of ὗδωρ, "water," might have inspired the need for the insertion of nu-movable — so an-ydria instead of the former a-hydria. The same could perhaps be said of the medieval scribe(s) of Theophrastus, for whom the diaeresis was a necessary sign that the now-unaspirated upsilon did not make a diphthong with the preceding alpha. Bill Berg