ἀπιστητέον
From LSJ
ἀσκέειν, περὶ τὰ νουσήματα, δύο, ὠφελέειν, ἢ μὴ βλάπτειν → strive, with regard to diseases, for two things — to do good, or to do no harm | as to diseases, make a habit of two things — to help, or at least, to do no harm
English (LSJ)
A one must mistrust, disbelieve, c. dat., Plb.4.41.8; of persons, Str.8.4.10, etc.; ἀ. ἡμῖν περί . . Hp.Cord.2.
Greek (Liddell-Scott)
ἀπιστητέον: ῥημ. ἐπίθ. τοῦ ἀπιστῶ, δεῖ ἀπιστεῖν, πρέπει τις νὰ ἀπιστῇ ἢ νὰ δυσπιστῇ, μετὰ δοτ., Πολύβ. 4. 41, 8, Στράβ. 362.
Spanish (DGE)
no hay que creer, hay que desconfiar c. dat. de cosa τῷ μεγέθει ... τῷ πλήθει Plb.4.41.8
•c. dat. de pers. ἡμῖν περί ... Hp.Cord.2, τῷ φήσαντι Str.8.4.10.