An unlawful alienation of lands, or tenements to any corporation, sole or aggregate, ecclesiastical or temporal. These purchases having been chiefly made by religious houses, in consequence of which lands became perpetually inherent in one dead hand, this has occasioned the general appellation of mortmain to be applied to such alienations.Mortmain is also employed to designate all prohibitory laws, which limit, restrain, or annul gifts, grants, or devises of lands and other corporeal hereditaments to charitable uses.