ἐπιτηδευτέον
From LSJ
κάλλιστον ἐφόδιον τῷ γήρᾳ ἡ παιδεία (Aristotle, quoted by Diogenes Laertius 5.21) → the finest provision for old age is education
English (LSJ)
A onemust pursue, Pl.Lg. 858d. Adj. -τέος, α, ον, to be pursued, Plu.2.10b.
Greek (Liddell-Scott)
ἐπιτηδευτέον: ῥημ. ἐπίθ. τοῦ ἐπιτηδεύω, δεῖ ἐπιτηδεύειν, Πλάτ. Νόμ. 858D.