Dissertátio, onis, f. g. Ipse dissertandi actus. Pli. Disputation: reasoning: debating: contention.
Lewis and Short: Latin dictionary
dissertātĭo, ōnis, f. [disserto], a spoken dissertation, discourse, disquisition (not a written treatise; cf. disputatio; late Lat.), Gell. 1, 2, 6; 10, 4, 1; 14, 3, 5 (in Plin. 10, 68, 87, 190, the true reading is edissertatio) al.