Definition - What does Trust Instrument mean?
A trust instrument is a legally binding document that is used as an instrument to officially set up a trust. Deeds, wills, declarations of trust, or agreements can all act as instruments of trust. Information on a trust instrument can include the beneficiaries of the trust, the managers of the trust, the exact details of how the trust will be carried out, etc.
Justipedia explains Trust Instrument
Trusts are set up so that a third party can manage assets for beneficiaries. For example, a grandfather may set up a trust for his grandson, and put $200,000 and three acres of land in the trust. The grandfather may use his will as a trust instrument in this case. By doing so, he would create the trust, which would then be carried out according to his desires, and in accordance with the law. The grandson would receive the assets in the manner that the grandfather laid out.