on·o·mas·tic 
(ŏn′ə-măstĭk)
(ŏn′ə-măstĭk)adj.
1. Of, relating to, or explaining a name or names.
2. Of or relating to onomastics.
[French onomastique, from Greek onomastikos, from onomazein, to name, from onoma, name; see n-men- in the Appendix of Indo-European roots.]