θρεπ-τέος · threp-teos — LSJ
to be fed, nurtured
to be fed, nurtured, metaph., γυμναστικῇ Pl. R. 403c.
II one must feed, keep
θρεπτέον one must feed, keep, Id. Ti. 19a, X. Lac. 9.5.
2 one must live
(from Pass.) ἢ ἐργαστέον ἢ ἀπὸ τῶν εἰργασμένων θρεπτέον one must live on what has been earned, Id. Eq.Mag. 8.8.