bona vacantia
Concise Oxford English Dictionary © 2008 Oxford University Press:
bona vacantia /ˌbəʊnə vəˈkantɪə/
▶noun Law (in the UK) goods without an apparent owner, to which the Crown may have right.
– origin L., ‘ownerless goods’.
'bona vacantia' also found in these Oxford entries:

