δεικτέον
From LSJ
ἔτυχες εἰς τὴν μάχην ὑπὸ τοῦ στρατηγοῦ πεμφθεὶς → you happened to be sent into the battle by the general
English (LSJ)
A one must show, prove, X.Mem.3.5.8; περίτινος Thphr. CP3.7.5; τοὺς νόμους δεικτέον μοι it is my duty to point out .., D.18.58, cf. Porph.Abst.3.7.
Spanish (DGE)
1 hay que mostrar τοὺς νόμους D.18.58, τοῦτ' αὖ δ. ... προσῆκον αὐτοῖς X.Mem.3.5.8
•hay que demostrar c. part. pred., Plb.12.8.1, ὅτι Luc.Par.13, Euc.10.17.
2 hay que explicar o dar una explicación οὐκ ἐγχωρεῖ λαβεῖν ὅρους, ἐκ δὲ τοῦ ἀδιορίστου δ. Arist.APr.27b20, ὑπὲρ ἧς Thphr.CP 3.7.5, περὶ τοῦ ἑξῆς Aristox.Harm.66.1, περὶ ὧν Lyd.Mag.1.46.
3 hay que servir de guía Plot.1.3.3.
Dutch (Woordenboekgrieks.nl)
δεικτέον, adj. verb. van δείκνυμι er moet bewezen worden.