prae·no·men 
(prē-nōmən)
(prē-nōmən)n. pl. prae·no·mens or prae·nom·i·na (-nŏmə-nə, -nōmə-)
1. A first or given name.
2. The first name of a citizen of ancient Rome, as Gaius in Gaius Julius Caesar.
[Latin praenōmen : prae-, pre- + nōmen, name; see n-men- in the Appendix of Indo-European roots.]
prae·nomi·nal (-nŏmə-nəl) adj.