The term "co-brother" refers to the husband of one's sibling. However, several synonyms exist for this relationship, depending on cultural and linguistic contexts. In English, "brother-in-law" is commonly used when referring to the spouse of one's sister or brother. Other alternatives include "sibling-in-law" and "in-law brother." In some cultures, such as Hindi-speaking communities, "jijaji" or "sisters-wala-bhai" is the preferred term for a brother-in-law. Similarly, in Chinese, "xiong di" or "brother" is used to refer to the husband of one's sister. The use of these synonyms depends on the social and familial context of the relationship.