Hefker

Hefker (Hebrew: הפקר) is ownerless property under rabbinic law. While some property is intrinsically ownerless, ordinary property can be made ownerless by the formal renunciation of its owner or by judicial action (as shown in Gittin 36b). Even absent such an action, property will become ownerless if the owner was a convert to Judaism who dies without Jewish heirs (as seen in Bava Batra 149a). Hefker re-emerged in the early 20th century as a symbol in European Hebrew and Yiddish literature.