Ingenuus

In Roman law. A person who, immediately that he was born, was a free person. He was opposed to libertinus, or libertus, who, having been born a slave, was afterwards manumitted or made free. It is not the same as the English law term "generosus," which denoted a person not merely free, but of good family. There were no distinctions among ingenui; but among libertini there were (prior to Justinian's abolition of the distinctions) three varieties, namely: Those of the highest rank, called "Cives Romani;" those of the second rank, called "Latini Juniani;" and those of the lowest rank, called "Dediticii."

Brown.