What does a circular definition entail?

A circular definition refers back to the term itself, meaning it defines a word using the word itself or a variant of it. This type of definition is generally unhelpful because it does not provide additional information or clarification. For example, if someone defines "feline" as "a feline animal," it does not contribute to understanding what a feline actually is, since it simply restates the term without offering any new context or details. This characteristic highlights the inadequacy of circular definitions, as they do not fulfill the primary role of a definition, which is to explain the meaning of a term in a way that is comprehensible and informative.