A "unic" is not a known term. However, "eunuch" is a term that refers to a male who has been castrated. Throughout history, castration has often served a specific social function. The earliest records for intentional castration to produce eunuchs are from the Sumerian city of Lagash in the 2nd millennium BCE. The Bibles teachings on eunuchs are varied, from the inability to serve as priests to special promises by God. Eunuchs can be natural, forced, or voluntary. Natural eunuchs include those who are born with a physical defect, but they also comprise those who are born with no real desire for marriage or sex. Forced eunuchs are those who have been castrated for whatever reason. Voluntary eunuchs are those who, in order to better serve the Lord in some capacity, choose to forego marriage.