Entry 2 senses · 2 variants Webster, 1913 Cognominal · Cog·nom·i·nal · IPA /kɒɡˈnɒmɪnəl/ a. n. 01 a. Of or pertaining to a cognomen; of the nature of a surname. 1. Of or pertaining to a cognomen; of the nature of a surname. 02 n. One bearing the same name; a namesake. 1. One bearing the same name; a namesake.[Obs.]