Definition of "nomen"

Greeks and other provincials who gained Roman citizenship kept their Greek names as cognomens, to which they added Roman nomens and praenomens—usually those of the ones to whom they owed their citizenship.

1990, Richard N. Longenecker, Galatians (Word Biblical Commentary; 41), Zondervan, page 2

The adytum is unsculptured, but two monoliths within it bear the name of Physcon and Cleopatra; and in the front chamber of the naos is that of the Ethiopian king “Ashar (Atar)-Amun*, the everliving,” who in some of his nomens is called “the beloved of Isis.”

1843, [John] Gardner Wilkinson, Modern Egypt and Thebes: Being a Description of Egypt; Including the Information Required for Travellers in That Country, volume II, London: John Murray, […], page 308

The following is a list of the prenomens and nomens of Egyptian kings which are of common occurrence, with transliterations into Roman letters.

1906, E[rnest] A[lfred] Wallis Budge, Cook’s Handbook for Egypt and the Sûdân, 2nd edition, London: Tho[ma]s Cook & Son, […]; Simpkin, Marshall, Hamilton, Kent & Co., Ltd., page 189