ῥοϊσμός
From LSJ
ὀψὲ θεῶν ἀλέουσι μύλοι, ἀλέουσι δὲ λεπτά → the millstones of the gods grind late, but they grind fine | the mills of God grind slowly, but they grind exceedingly small
English (LSJ)
ὁ, (ῥοΐζω) A = ὁ τῶν ἵππων ῥισμός (sic), Hsch.
Greek (Liddell-Scott)
ῥοϊσμός: ὁ, (ῥοΐζω) κολύμβημα, ἐπὶ ἵππων, «ροϊσμός· ὁ τῶν ἵππων» Ἡσύχ.