A written agreement between the issuer of debt securities (such as bonds, notes, or debentures) and the representative of security holders (the trustee) in relation to such securities. The agreement defines and outlines the terms and conditions of the debt securities, including the interest rate, methods of payment, maturity, any redemption terms, timing, and any covenants, action in the event of default, and any other mutually negotiated terms and conditions (e.g., the duties of the issuer and the trustee).

A deed of trust is a legal contract issued to lenders, outlining and setting out commitments and responsibilities of the seller and buyer of a certain bond issue.

It is also known as a bond indenture or a trust indenture.