κιθαριστέον
From LSJ
ἀνδρῶν γὰρ σωφρόνων μέν ἐστιν, εἰ μὴ ἀδικοῖντο, ἡσυχάζειν → for it is the part of prudent men to remain quiet if they should not be wronged
English (LSJ)
A one must play the cithara, Pl.Sis. 389c.
Greek (Liddell-Scott)
κῐθᾰριστέον: ῥημ. ἐπίθετ., δεῖ καθαρίζειν, Πλάτ. Σίσυφ. 389C.
Dutch (Woordenboekgrieks.nl)
κιθαριστέον, adj. verb. van κιθαρίζω, er moet op de citer worden gespeeld.