As used in this subchapter:
(1) “State” includes any territory of the United States and District of Columbia.
(2) “Summons” includes a subpoena, order or other notice requiring the appearance of a witness.
(3) “Witness” includes a person whose testimony is desired in any proceeding or investigation by a grand jury or in any criminal proceeding.
41 Del. Laws, c. 214, § 1; 11 Del. C. 1953, § 3521.