πιστευτέον
From LSJ
ψυχῆς πείρατα ἰὼν οὐκ ἂν ἐξεύροιο πᾶσαν ἐπιπορευόμενος ὁδόν· οὕτω βαθὺν λόγον ἔχει → one would never discover the limits of soul, should one traverse every road—so deep a measure does it possess
English (LSJ)
A one must trust, Pl.Ti.20b, 40e, Arist.GA760b31, Str.15.1.34. II one must believe, Plb.12.11.3, Str.1.3.1; τῷ θρυλουμένῳ Longin.44.2; εἰ τοῦτο π. κατ' ἐκείνου Aristid.Or.20(21).9 : in plural -ευτέα, οὐκέτι π. τῶν νῦν οὐδενί Luc.Tim.48.
Greek (Liddell-Scott)
πιστευτέον: ῥηματ. ἐπίθ. τοῦ πιστεύω, δεῖ πιστεύειν, Πλάτ. Τίμ. 20Β, 40Ε, Στράβ. 702.
Dutch (Woordenboekgrieks.nl)
πιστευτέον, adj. verb. van πιστεύω, er moet vertrouwd worden:. οὐκέτι πιστευτέα τῶν νῦν οὐδενί men moet niemand van de mensen van tegenwoordig meer vertrouwen Luc. 25.48.