A eunuch ( YOO-nək)  is a man who has been castrated. Throughout history, castration 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. Over the millennia since, they have performed a wide variety of functions in many different cultures: courtiers or equivalent domestics, for espionage or clandestine operations, castrato singers, concubines, or sexual partners, religious specialists, soldiers, royal guards, government officials, and guardians of women or harem servants. Eunuchs would usually be servants or slaves who had been castrated to make them less threatening servants of a royal court where physical access to the ruler could wield great influence. Seemingly lowly domestic functions—such as making the rulers bed, bathing him, cutting his hair, carrying him in his litter, or even relaying messages—could, in theory, give a eunuch "the rulers ear" and impart de facto power on the formally humble but trusted servant. Similar instances are reflected in the humble origins and etymology of many high offices. Eunuchs supposedly did not generally have loyalties to the military, the aristocracy, or a family of their own (having neither offspring nor in-laws, at the very least). They were thus seen as more trustworthy and less interested in establishing a private "dynasty". Because their condition usually lowered their social status, they could also be easily replaced or killed without repercussion. In cultures that had both harems and eunuchs, eunuchs were sometimes used as harem servants.
The emperor also goes further than Orion by attributing eunuchs lack of male-female intercourse specifically to castration, which he said was performed with the intention "that they will no longer do the things that males do, or at least to extinguish whatever has to do with desire for the female sex". The 11th century Byzantine monk Nikon of the Black Mountain, opting instead for Orions second alternative, stated that the word came from eunoein (eu "good" + nous "mind"), thus meaning "to be well-minded, well-inclined, well-disposed or favorable", but unlike Orion he argued that this was due to the trust that certain jealous and suspicious foreign rulers placed in the loyalty of their eunuchized servants. Theophylact of Ohrid in a dialogue In Defence of Eunuchs also stated that the origin of the word was from eupnoeic and ekhein, "to have, hold", since they were always "well-disposed" toward the master who "held" or owned them. The 12th century Etymologicum Magnum (s.v. eunoukhos) essentially repeats the entry from Orion, but stands by the first option, while attributing the second option to what "some say". In the late 12th century, Eustathius of Thessalonica (Commentaries on Homer 1256.30, 1643.16) offered an original derivation of the word from eunis + okheuein, "deprived of mating".