The term "risk-free interest rate" refers to the theoretical interest rate that an investment would earn if there was no risk of default or loss of principal. However, there are several synonyms that can be used to refer to this concept. For instance, the risk-free rate may also be called the "zero-risk interest rate" or the "baseline interest rate." Other terms that can be used include the "default-free rate," the "benchmark interest rate," or the "safe rate." Regardless of the term used, the risk-free rate is an important concept in finance and serves as a benchmark for determining the expected return on investments with varying degrees of risk.