A supplemental agreement, attached to and made a part of a Life Insurance policy, setting forth the manner in which the proceeds are to be paid, in lieu of having them paid in a lump sum or under one of the other installment settlement options in the policy itself. (2) An agreement or instrument under which a corpus (fund/property) is given over to the management of the trustee named in a trust instrument for the benefit of the beneficiaries of the trust. (3) A written agreement between two parties – the employer and the trustee- setting forth the provisions of a pension plan.