συνεθιστέον
From LSJ
τί δὲ βλέπεις τὸ κάρφος τὸ ἐν τῷ ὀφθαλμῷ τοῦ ἀδελφοῦ σου, τὴν δὲ ἐν τῷ σῷ ὀφθαλμῷ δοκὸν οὐ κατανοεῖς → why do you look at the speck of sawdust in your brother's eye and pay no attention to the plank in your own eye | and why beholdest thou the mote that is in thy brother's eye, but considerest not the beam that is in thine own eye | why do you see the speck that is in your brother's eye, but don't consider the beam that is in your own eye
English (LSJ)
A one must accustom oneself, c. inf., Pl.R.520c. II one must accustom, πρὸς ταῦτα σ. αὑτούς, folld. by infs., Plu.2.522d.
Greek (Liddell-Scott)
συνεθιστέον: ῥηματ. ἐπίθετ., πρέπει τις νὰ συνηθίσῃ ἑαυτόν, Πλάτ. Πολ. 520C. II. πρέπει τις νὰ συνηθίσῃ, τινὰ πρός τι Πλούτ. 2. 522D· τινὰ ποιεῖν τι αὐτόθι 11C.