διαγιγνώσκω · diagignōskō — LSJ
know one from the other, distinguish, discern, εὖ διαγιγνώσκοντες Il. 23.240; ἔνθα διαγνῶναι χαλεπῶς ἦν ἄνδρα ἕκαστον 7.424, cf. Ar. Pl. 91; δ. εἰ ὅμοιοί εἰσι to distinguish whether they are equals or no, Hdt. 1.134; οὐδʼ ἂν . . διαγνοίη, λίνου ἢ καννάβιός ἐστι Id. 4.74; δ. τὴν βοὴν ὁποτέρα μείζων Th. 1.87; δ. διότι . . Arist. Pol. 1266b16; δ. πότερον . ., ἤ . . Id. Mete. 389a5; δ. τὸν καλόν τε καὶ αἰσχρὸν ἔρωτα Pl. Smp. 186c; δ. τὸ ὀρθὸν καὶ μή Aeschin. 3.199; δ. τὴν θήλειαν καὶ τὸν ἄρρενα Aris
discern exactly, perceive, descry, τι S. El. 1186; δ. ὅτι . . Isoc. 3.47.
Medic., form a diagnosis, Erasistr. ap. Gal. 8.14.
determine by vote or otherwise, c. inf., Hdt. 6.138, Luc. Am. 9, Hdn. 4.4.2:—Pass., impers. διέγνωστο αὐτοῖς λελύσθαι τὰς σπονδάς Th. 1.118.
law-term, determine or decide a suit, δίκην A. Eu. 709, cf. IG 5(2).159 (Tegea, v B. C.), Antipho 6.3; τὰ ἀμφισβητήσιμα Id. 2.1.1; give judgement, περί τινος Th. 4.46, Lys. 7.22, D. 28.10; take cognizance of an action, PPetr. 3p.118 (iii B. C.), etc.:—Pass., διεγνωσμένη κρίσις Th. 3.53; μενέτωσαν ἐν τοῖς διαγνωσθεῖσι Lex ap. D. 21.94.
= διαναγιγνώσκω (which shd. perh. be read), read through, Plb. 3.32.2, Ph. 2.555, al.