ἐθελουσίως

From LSJ

ἔνδον γὰρ ἁνὴρ ἄρτι τυγχάνει, κάρα στάζων ἱδρῶτι καὶ χέρας ξιφοκτόνους → yes, the man is now inside, his face and hands that have slaughtered with the sword dripping with sweat

Source

French (Bailly abrégé)

adv.
volontairement.
Étymologie: ἐθελούσιος.

Spanish

por propia voluntad, espontáneamente

Russian (Dvoretsky)

ἐθελουσίως: Xen. = ἐθελοντηδόν: по своей воле, добровольно.