ἐξόπλισις
From LSJ
προγράψαντες οὖν τά τε θεωρήματα καὶ τὰ ἐπιτάγματα τὰ χρεῖαν ἔχοντα εἰς τὰς ἀποδείξιας αὐτῶν μετὰ ταῦτα γραψοῦμές τοι τὰ προκείμενα → having therefore written at the beginning the theorems and the postulates that are necessary for their proofs, we will then write out for you the propositions
English (LSJ)
εως, ἡ,
A getting under arms, πολλοῦ χρόνου δέονται εἰς ἐξόπλισιν X.Cyr.8.5.9, cf. Arist.Pr.922b14.