Assertio, assertiònis, f. g. Cic.An affirmance: also after Bude a demonstration: a document: a vouching. Also a procuring of ones libertie.
Lewis and Short: Latin dictionary
assertĭo (ads-), ōnis, f. [2. assero]. I.Lit. (acc. to 2. assero, I. A.), a formal declaration that one is a freeman or a slave: adsertio tam a servitute in libertatem, quam a libertate in servitium trahi significat, Prisc. p. 1208 P.; Traj. ap. Plin. Ep. 10, 72 fin.: perfusoriae adsertiones,
unauthorized declarations of freedom
, Suet. Dom. 8: sitne liber qui est in adsertione, Quint. 3, 6, 57: ut in reis deportatis et adsertione secundā (i. e. judicio secundo, in quo adsertor de libertate agit), id. 5, 2, 1; so also id. 11, 1, 78; cf. Cod. Just. 7, 17, 1.— II. In gen., an assertion (late Lat.), Arn. 1, p. 18: deorum adsertio religiosa,