Mass. Gen. Laws ch. 33 § 1
As used in this chapter, the following words shall, unless the context clearly requires otherwise, have the following meanings:
"Commander-in-chief", the governor of the commonwealth.
"Enlisted person", a member, other than a commissioned officer or a warrant officer, in the military forces of the commonwealth.
"Military custodian", the senior military officer in command of troops stationed in an armory or air installation unless otherwise designated by the commander-in-chief.
"Military forces of the commonwealth", shall include the organized militia, as defined in section 4, and members of the unorganized militia, as defined in section 3, if drafted or accepted as volunteers under sections 55 and 56.
"Noncommissioned officer", an enlisted person serving at a rank of corporal through command sergeant major in the army national guard or staff sergeant through command chief master sergeant in the air national guard.
"Officer", a commissioned officer or a warrant officer in the military forces of the commonwealth.
"Organization", a command composed of 2 or more units.
"Unit", shall include headquarters, detachment, company, battery, troop and equivalent air unit and such other elements as may be determined by the commander-in-chief to come under such designation.
Mass. Gen. Laws ch. 33, § 1