For the purposes of this subchapter—

((a)) The term “Board” means the Board of Regents of the Smithsonian Institution.

((b)) The term “Commission” means the National Portrait Gallery Commission as provided for in this subchapter.

((c)) The term “Gallery” means the National Portrait Gallery established by this subchapter.

((d)) The term “gift” includes a gift, bequest, or devise, whether outright or in trust, and any legal instrument by which the gift is effected.

((e)) The term “portraiture” includes portraits and reproductions thereof made by any means or process, whether invented or developed heretofore or hereafter.