In this chapter:
"Estate" means the gross estate of a decedent as determined for the purpose of federal estate tax and the estate tax payable to this state;
"Fiduciary" means executor, administrator of any description, and trustee;
"Person" means any individual, partnership, association, joint stock company, corporation, government, political subdivision, governmental agency, or local governmental agency;
"Person interested in the estate" means any person including an executor, administrator, guardian, conservator or trustee, entitled to receive, or who has received, from a decedent while alive or by reason of the death of a decedent any property or interest therein included in the decedent's taxable estate;
"State" means any state, territory, or possession of the United States, the District of Columbia, or the Commonwealth of Puerto Rico; and
"Tax" means the federal estate tax and the additional estate tax imposed by the State of Mississippi and interest and penalties imposed in addition to the tax.