1. : the easement or servitude acquired by grant or by prescription by which an owner of a structure on land has a right to rest or support it in whole or in part upon the land or structure of an adjoining owner (as by inserting beams in the adjoining wall on the boundary)
2. : the common law easement right of an owner of land to have his soil (as distinguished from the structures thereon) both lateral and subjacent remain in its natural condition without being moved or caused to subside without his consent