A more thorough explanation:

Definition: Manus mortua is a Latin term that means "dead hand." It refers to the condition of lands or tenements held in perpetuity by an ecclesiastical or other corporation. Mortmain is a French term that means "dead hand" and is used interchangeably with manus mortua.

Example: Land alienated in mortmain is not inalienable, but it will never escheat or pass by inheritance because a corporation does not die. For example, a church may own a piece of land in perpetuity, and even if the church dissolves, the land will still belong to the church's successor organization.

Explanation: The example illustrates how a corporation can hold land in perpetuity, even if the organization that originally owned the land no longer exists. This is because a corporation does not die, and the land will always belong to the organization's successor. This concept is important in estate planning and tax law because land held in mortmain is not subject to inheritance taxes.