onomastic (on-<<schwa>>-mas-tik), adj.1. Of or relating to names or nomenclature. 2. (Of a signature on an instrument) in a handwriting different from that of the body of the document; esp., designating an autograph signature alone, as distinguished from the main text in a different hand or in typewriting. Cf. HOLOGRAPH; SYMBOLIC. — onomastics (for sense 1), n.

[Blacks Law 8th]