Md. Code, Courts and Judicial Proceedings § 9–301

(a) In this title the following words have the meanings indicated.

(b) “State” means any state or territory of the United States and the District of Columbia.

(c) “Summons” means a subpoena, order, or other notice requiring the appearance of a witness.

(d) “Witness” means a person whose testimony is desired in any proceeding or investigation by a grand jury or in a criminal prosecution or proceeding.