retrocession

Short definition from Wiktionary

Noun

1. 1
   The transfer of risk from one reinsurer to another.
2. 2
   The return of land, rights, etc. previously ceded.
3. 3
   Metastasis of an eruption or tumour from the surface to the interior of the body.
4. 4
   The act of retroceding; a going back.