bona vacantia
/ˌbəʊnəvəˈkæntɪə/noun
mass noun
- Law (in the UK) goods without an apparent owner, such as treasure trove or the estate of a person dying intestate and without heirs, to which the Crown may have right【律】（英国）无主财物（如发掘出来的物主不明的财物或无继承人的财产, 属国王所有）。
词源
Latin, 'ownerless goods'.