ˈprɒsɪlaɪt
A person who has converted from one religion or belief to another, especially to Judaism.
But woe unto you, scribes and Pharisees, hypocrites! for ye shut up the kingdom of heaven against men: for ye neither go in yourselves, neither suffer ye them that are entering to go in. Woe unto you, scribes and Pharisees, hypocrites! for ye devour widows' houses, and for a pretence make long prayer: therefore ye shall receive the greater damnation. Woe unto you, scribes and Pharisees, hypocrites! for ye compass sea and land to make one proselyte, and when he is made, ye make him twofold more the child of hell than yourselves.
Matthew 23:13-15, KJV
προσήλυτος /proselutos/
Koine Greek, Eastern Mediterranean
proselytus /proselytus/
Late Latin, Roman Empire