adsertio
From LSJ
εἰ ἀποκρυπτόντων τῶν Μήδων τὸν ἥλιον ὑπὸ σκιῇ ἔσοιτο πρὸς αὐτοὺς ἡ μάχη καὶ οὐκ ἐν ἡλίῳ → if the Medes hid the sun, the battle would be to them in the shade and not in the sun
Latin > English
adsertio adsertionis N F :: act of claiming free or slave (for status); defense/vindication (of character)
Latin > French (Gaffiot 2016)
adsertĭō¹⁵ (ass-), ōnis, f.,
1 action de revendiquer pour qqn la condition de personne libre [ou d’esclave] : Quint. 3, 6, 57 ; adsertionem denegare alicui Traj. d. Plin. Min. Ep. 10, 66, 2, refuser à qqn le droit de revendiquer la condition d’homme libre
2 affirmation, assertion : Aug. Ep. 202, 8 ; Arn. 1, 32, etc.