σκληρυσμός
From LSJ
ἔστιν δέ που ἡ μὲν ἐπὶ σώμασι γυμναστική, ἡ δ' ἐπὶ ψυχῇ μουσική → I think I am right in saying that we have physical exercise for the body and the arts for the soul
English (LSJ)
ὁ, hardening, induration, Id.Prorrh.1.19, cf. Coac.98, Antyll. ap. Orib. 45.15.5.
Greek (Liddell-Scott)
σκληρυσμός: ὁ, τὸ σκληρύνειν, ἐπιφέρειν σκλήρυνσιν, Ἱππ. Προρρ. 68, πρβλ. 131D, κτλ.
Greek Monolingual
Dutch (Woordenboekgrieks.nl)
σκληρυσμός -ου, ὁ [σκληρύνω] verharding.