Lewis & Short

Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.

Ŏlĭsīpo and Ŏlysippo (Ulys-), ōnis, m., a city of Lusitania, the modern Lisbon, Plin. 4, 22, 35, § 116; 8, 42, 67, § 166: Olysippo, Varr. R. R. 2, 1, 19: Ulysippo, Mela, 3, 1, 6.
Hence, Ŏlĭsīpōnensis (Olys-), e, adj., of or belonging to Olisipo: promontorium, Plin. 4, 21, 35, § 113.
Plur. subst.: Ŏlĭsīpōnenses, ĭum, m., the inhabitants of Olisipo, the Olisiponians, Plin. 9, 5, 4, § 9.