ἀπογνωστέον
From LSJ
Ἔοικα γοῦν τούτου γε σμικρῷ τινι αὐτῷ τούτῳ σοφώτερος εἶναι, ὅτι ἃ μὴ οἶδα οὐδὲ οἴομαι εἰδέναι → I seem, then, in just this little thing to be wiser than this man at any rate, that what I do not know I do not think I know either
English (LSJ)
A one must give up in despair, ἐλπίδας Ph.1.455, cf. Aristaenet.1.17. 2 one mustreject the view, Plot.4.9.2: c.gen.,Simp.in Ph.610.9.
Greek (Liddell-Scott)
ἀπογνωστέον: ῥηματ. ἐπίθ. τοῦ ἀπογιγνώσκω, δεῖ ἀπογιγνώσκειν, οὐκ ἀπογνωστέον τοῦ κοινοὺς ἅπασι νόμους γενέσθαι Συνέσ. 154C.
Spanish (DGE)
1 hay que abandonar τὰς ... ἐλπίδας Ph.1.455, cf. Aristaenet.1.17.20.
2 hay que desechar, rechazar συμπάσχειν μὲν οὐκ ... ἀπογνωστέον no hay que descartar una simpatía Plot.4.9.2, c. gen., Simp.in Ph.610.9.