Lewis & Short

Lū̆crētĭlis, is, m., a mountain in the Sabine territory, now Monte Genaro, Hor. C. 1, 17, 1; cf.: Lucretilis mons in Sabinis, Paul. ex Fest. p. 119 Müll.
Hence, Lū̆-crētīnus, a, um, adj., of or near the mountain Lucretilis, where Atticus had a villa: sol, Cic. Att. 7, 11, 1 Klotz (dub.; v. lucrativus, I.).