Which term refers to the third level in a hierarchical classification system?

The term that refers to the third level in a hierarchical classification system is "tertiary." In biological classification, organisms are grouped into a hierarchy that includes levels such as domain, kingdom, phylum, class, order, family, genus, and species. The tertiary level is typically associated with the third level of classification, which means it refers to a more specific grouping within that hierarchy. The term "secondary" relates to the second level, while "quaternary" designates the fourth level in the classification system. Understanding these levels helps in categorizing organisms based on shared characteristics and evolutionary relationships.