Next of kin is a term used to describe someone's closest living relative. However, there are several other synonyms for next of kin that can be used depending on the context. These include immediate family, blood relation, nearest and dearest, closest relative, family member, heir, kinsman, and relation. Each of these words can be used to describe someone's closest family member or relative in different scenarios. For example, immediate family is often used to refer to a person's spouse and children, while closest relative can refer to any family member who is most closely related to the person in question.