the direct line of descent or blood relation

handed down in a direct line from the founder

closely related by blood

son, especially the eldest son, of the legal wife (contrasted with [[庶子|庶子|shu4 zi3]])

father's primary wife (term used by the children of a concubine to address their father's primary wife)

born of the legal wife (not of a concubine)

the eldest son born to the primary wife of a man, traditionally having the primary right of inheritance

having the same paternal grandfather but different fathers