High-risk bonds, also known as junk bonds or speculative bonds, are those that have a higher probability of default compared to investment-grade bonds. There are several other synonyms for high-risk bonds, including sub-investment-grade bonds, non-investment-grade bonds, below-investment-grade bonds, and low-rated bonds. Additionally, some investors refer to them as distressed or troubled debt, reflecting the inherent risks and potential for loss associated with these types of investments. Despite the higher level of risk, high-risk bonds can offer attractive returns for investors who are willing to take on the added risk and uncertainty that comes with these securities.