Mass. Gen. Laws ch. 160 § 1
The following words as used in this chapter, unless the context otherwise requires, shall have the following meanings:
"Board of aldermen" or "selectmen" includes the board or other authority exercising the powers of a board of aldermen or of selectmen; but nothing herein shall be construed as affecting the veto power of a mayor of any city.
Department, the department of public utilities.
"Public way", any way laid out by public authority.
"Railroad", a railroad or railway of the class usually operated by steam power.
"Railroad corporation", the corporation which lays out, constructs, maintains or operates a railroad of the class usually operated by steam power.
"Railroads and railways", all railroads and railways except tramways in mines and marine railways.
Mass. Gen. Laws ch. 160, § 1