You are strongly recommended to add to your library the excellent revised edition of Harper's Bible Dictionary titled, The Harper Collins Bible Dictionary, Revised Edition [book review], edited by Paul J. Achtemeier, with the Society of Biblical Literature (NY: Harper Collins, 1996). It is currently the best one-volume Bible dictionary in English, and it is available at Border's Books, Christian Science Reading Rooms, http://www.borders.com, or http://www.christianbook.com.

eunuch, a male who has been castrated. Eunuchs were in demand as guards of royal harems. Consequently, most biblical references to these persons who by accident or design had lost their capacity to procreate come from narratives about the kings and their courts. Although excluded from the sacred assembly (Deut. 23:1), eunuchs often received favorable report (one rescued Jeremiah; cf. the Ethiopian eunuch in Acts 8:27). Becoming a eunuch for religious reasons is mentioned in Matt. 19:12, although the exact meaning of that verse is unclear. It is probably metaphorical for remaining celibate to serve God better (cf. 1 Cor. 7:32-34).

To explore Jesus' view of eunuchs, see http://www.bibletexts.com/qa/qa133.htm#eunuchs.