Correct spelling for the English word "Gentilitious" is [d͡ʒˌɛntɪlˈɪʃəs], [dʒˌɛntɪlˈɪʃəs], [dʒ_ˌɛ_n_t_ɪ_l_ˈɪ_ʃ_ə_s] (IPA phonetic alphabet).
Peculiar to a people or nation; hereditary.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.