交還,後退,內攻
Retrocession \Re`tro*ces"sion\, n. [Cf. F. r['e]trocession. See {Retrocede}.] 1. The act of retroceding. 2. The state of being retroceded, or granted back. 3. (Med.) Metastasis of an eruption or a tumor from the surface to the interior of the body.