An unsecured bond with a claim to assets that is subordinate to all existing and future debt. Thus, in the event that the issuer encounters financial difficulties and must be liquidated, all other claims must be satisfied before holders of subordinated debentures can receive a settlement. Frequently, this settlement amounts to relatively little. Because of the risk involved, the issuers have to pay relatively high interest rates in order to sell these securities to investors. See also convertible security.