παρέργως

From LSJ

πρὶν τοὺς ἰχθῦς ἑλεῖν σὺ τὴν ἅλμην κυκᾷς → you're mixing the sauce before catching the fish | don't count your chickens before they are hatched | don't count your chickens before they hatch | first catch your hare | first catch your rabbit | first catch your rabbit and then make your stew | first catch your hare, then cook it | first catch your hare, then cook him

Source

French (Bailly abrégé)

adv.
d'une manière accessoire ; superficiellement.
Étymologie: παρά, ἔργον.

Russian (Dvoretsky)

παρέργως: мимоходом, между прочим Plat., Dem.