Blue blood is a term that refers to people who belong to noble families or have high social status. However, there are several synonyms that can be used instead of blue blood. For example, the phrase "aristocratic pedigree" can be used to refer to people who come from noble families. Similarly, the term "patrician" can be used to describe people who belong to the upper class. "High-born" refers to individuals who are born into wealthy or noble families. Other synonyms include "noble," "elite," "upper crust," and "privileged." These terms can be used to describe people who have inherited wealth, status, or other privileges.