ἐρωτητέον
From LSJ
κρείσσων ἐναρχόμενος βοηθῶν καρδίᾳ τοῦ ἐπαγγελλομένου καὶ εἰς ἐλπίδα ἄγοντος· δένδρον γὰρ ζωῆς ἐπιθυμία ἀγαθή (Proverbs 13.12 LXX) → One who sincerely sets about helping is better than one who makes promises leading to hope; for a kindly urge is a tree of life.
English (LSJ)
verb. Adj.
A one must ask, ἐρώτημα Arist.APo.77b7.
Greek (Liddell-Scott)
ἐρωτητέον: ῥημ. ἐπίθ. τοῦ ἐρωτῶ, δεῖ ἐρωτᾶν, Ἀριστ. Ἀναλυτ. Ὕστ. 1. 12, 2.