"First-born" refers to the eldest child born to parents. However, there are several other synonyms that can be used to refer to this special family member. Some commonly used words include "eldest," "primary," and "initial." "Senior" is also a suitable synonym, as it implies a sense of superiority and respect that is accorded to the eldest child. Other potential alternatives include "patriarch", "matriarch," "head of the family," and "dean." Regardless of the word used, the first-born child often plays a significant role in the family dynamic, acting as a role model for younger siblings and serving as a source of pride and joy for their parents.