Mass. Gen. Laws ch. 182 § 1
The following words, as used in this chapter, shall, except as otherwise expressly provided in section two A, have the following meanings: "Association", a voluntary association under a written instrument or declaration of trust, the beneficial interest under which is divided into transferable certificates of participation or shares. "Secretary", the state secretary. "Department", the department of public utilities or the department of telecommunications and cable. When used in sections two to seven, inclusive, and twelve to fourteen, inclusive, of this chapter, the word "trust" shall, except as otherwise expressly provided in section two A, mean a trust operating under a written instrument or declaration of trust, the beneficial interest under which is divided into transferable certificates of participation or shares, other than a trust established for the sole purpose of exercising the voting rights pertaining to corporate stock or other securities in accordance with the terms of a written instrument.
Mass. Gen. Laws ch. 182, § 1