mostellum
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
Latin > English (Lewis & Short)
mostellum: v. Mostellaria.
Latin > French (Gaffiot 2016)
mostellum, ī, n., dim. de monstrum, spectre, fantôme : Gloss.