Post-natus
Defined in 3 dictionaries — Ballentine's (1916), Black's (1910), Kinney (1893)
Ballentine's Law Dictionary
James A. Ballentine · 1916
After born.
Black's Law Dictionary
Henry Campbell Black, M.A. · 1910
Born afterwards. A term applied by old writers to a second or younger son. It is used in private international law to designate a person who was born after some historic event, (such as the American Revolution or the act of union between England and Scotland,) and whose rights or status will be governed or affected by the question of his birth before or after such event.
A Law Dictionary and Glossary
George C. Kinney · 1893
or postnatus, I. After born; a second son, so called, as distinguished from the eldest; born after a particular period or event.