What terms mean in this chapter

As used in this chapter: "Employees trust" means any trust created by an employer as part of a stock bonus, pension, profit-sharing, or annuity plan for the exclusive benefit of some or all of the employer's employees, or their beneficiaries, to which contributions are made by the employer, or employees, or both, for the purpose of distributing in accordance with such plan to the employees, or their beneficiaries, the earnings or the principal, or both earnings and principal, of the trust fund, provided that it is impossible under the trust terms at any time prior to the satisfaction of all liabilities with respect to employees and their beneficiaries under the trust for any part of the corpus or income to be at any time used for or diverted to purposes other than the exclusive benefit of the employees, or their beneficiaries. "Employer" includes a group of employers creating a combined plan or trust for the benefit of their employees or the beneficiaries of the employees.