Lewis & Short

Xĕnŏphon, ontis, m., = Ξενοφῶν, a celebratea Greek historian and philosopher, born B. C. 445, a pupil of Socrates and a leader of the Greeks in the army of Cyrus the younger, Cic. Div. 1, 25, 52; id. Tusc. 5, 34, 99; id. Sen. 9, 30; id. Leg. 2, 22, 56; Varr. R. R. 1, 1, 8.
Hence, Xĕnŏphontēus or -īus, a, um, adj., = Ξενοφόντειος, of or belonging to Xenophon, Xenophontian: genus sermonis, Cic. Brut. 35, 132: Hercules, i. e. mentioned in his writings, id. Fam. 5, 12, 3.