ἦρξα

From LSJ

τὰ μέλλοντα τοῖς γεγενημένοις τεκμαίρεσθαι → determine the future on the basis of the past

Source

French (Bailly abrégé)

v. ἄρχω.

Russian (Dvoretsky)

ἦρξα: aor. к ἄρχω.