junk bond

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A corporate bond having a high yield and high risk of default.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun finance A bond (an instrument of debt) which is considered below "investment grade" due to a significant risk of default by the issuer. The interest rate is higher in order to compensate holders for that risk.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a (speculative) bond with a credit rating of BB or lower; issued for leveraged buyouts and other takeovers by companies with questionable credit