Therian in the English language has two distinct definitions:

• In taxonomy, the term refers to a member of Theria, a subclass of advanced mammals.

• In anthropology and in certain psychological/spiritual subcultures, therian refers to a variety of otherkin who identify with animals or shapeshifters; a person who believes in, possesses some characteristics of, or subscribes to the spiritual or shamanic (not the folkloric) definition of therianthropy or who belongs to the therianthropy subculture.