Mass. Gen. Laws ch. 161 § 1
In this chapter, unless the context otherwise requires, the following words 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 in this chapter shall affect the veto power of a mayor of a city.
"Company", a street railway company.
Department, the department of public utilities.
"Extension", any railway constructed by a street railway company in a city or town in addition to that authorized by its original location therein.
"Public way", any way laid out by public authority.
"Street railway" or "railway", a railway, including poles, wires or other appliances and equipment connected therewith, of the class operated by motive power other than steam, and usually constructed upon public ways and places.
Mass. Gen. Laws ch. 161, § 1