I.Passive not to perceive or know, ἄνδρ᾽ ἀγνοιήσασ᾽ from not recognising him, Od.: mostly with negat., οὐκ ἠγνοίησεν, i. e. he perceived or knew well, Il.; μηδὲν ἀγνόει learn all, Eur.: —c. acc. to be ignorant of, Hdt., attic; ἀγν. περί τινος Plat.; dependent clauses are added in part., τίς ἀγνοεῖ τὸν πόλεμον ἥξοντα; Dem.; or with a Conjunct., οὐδεὶς ἀγνοεῖ ὅτι.., id=Dem.; Pass. not to be known, Plat., etc.
II.absol. to go wrong, make a false step, etc.; ἀγνοῶν ignorantly, by mistake, Xen.