Accordingly with the Portuguese dictionary from Porto Editora (2001), damanense is, I quote: adjectivo 2 generos - referente a Damao, territorio do antigo Estado Portugues da India; substantivo 2 generos - natural ou habitante de Damao; (De Damao, top. + -ense) and diuense is, I quote again adjectivo 2 generos - referente a Diu, provincia do antigo Estado Portugues da India; substantivo 2 generos - natural ou habitante de Diu; (De Diu + -ense). The Portuguese/English and English/Portuguese dictionary from Porto Editora (2001) doesn´t give any translation of these two words. The Oxford Talking Dictionary (1998) has an entry on this issue. I quote Daman and Diu /dmn, diu/ a Union Territory in India, on the west coast north of Bombay; pop. (1991) 101,400; capital, Daman. It consists of the district of Daman and the island of Diu, and until 1987 was administered with Goa. Nothing is said about how the people from these places are called. What the Portuguese dictionary says is that a damanense can be an adjective describing whatever refers to Daman (Damao) or a noun referring to the inhabitants of that place. The same logic is followed to diuense. Since Im Portuguese and I do not know enough English I can not give Cecil further help. Mafalda Mascarenhas
