This Russian entry about the name mentions an additional possibility to the ones that you already described, namely that the name is a combination of Arabic دين (din) meaning "religion" and Persian آرا (ara) meaning "decorate, adorn". The latter element is already described in the main database in the entry for Delara.- https://imya.com/name/6151 (in Russian)On the same website, the entry for the Tajik and Uzbek form of the name (Dinora) expands a little bit on the possibility where the name is ultimately derived from Arabic دين (din) meaning "religion". It states that the name is derived from Arabic دينورا (dinura) meaning "religious". There is no information about 'dinura' on Wiktionary yet, but Google Translate at least transcribes it as 'dinura' instead of 'dinorah' like the Russian website does.- https://imya.com/name/6158 (in Russian)You might also want to compare the entry for the name Dinorah in the Submitted Names Database, which currently states that the name is derived from Aramaic 'denur' or 'dinur' meaning "of fire".
- https://imya.com/name/6151 (in Russian)
On the same website, the entry for the Tajik and Uzbek form of the name (Dinora) expands a little bit on the possibility where the name is ultimately derived from Arabic دين (din) meaning "religion". It states that the name is derived from Arabic دينورا (dinura) meaning "religious". There is no information about 'dinura' on Wiktionary yet, but Google Translate at least transcribes it as 'dinura' instead of 'dinorah' like the Russian website does.
- https://imya.com/name/6158 (in Russian)
You might also want to compare the entry for the name Dinorah in the Submitted Names Database, which currently states that the name is derived from Aramaic 'denur' or 'dinur' meaning "of fire".