noun
head of a family; first name on a list
Refers to the person whose name appears first in a register or list, often the family head in official documents.
戸籍の筆頭者は父です。
The head of the family on the family register is my father.
名簿の筆頭者として彼の名前が載っている。
His name is listed as the first name on the roster.