High-Yield Bond

A bond with a low rating. Bonds rated less than Baa3 by Moody's or BBB- by S&P or Fitch are considered high-yield bonds. 

They have higher yields because they have a higher risk of default on the part of the issuer. 

High-yield bonds are considered sufficiently high-risk that the law does not allow banks to invest in them. 

They are also called low-grade bonds, and, informally, junk bonds.