Complex sentence: The origin of the term "Okinawa" remains unclear, though there was a divine woman named "Uchinaa" in the book "Omoro Sōshi", a compilation of ancient poems and songs from Okinawa Island.
Split into simpler sentences: The origin of the term "Okinawa" remains unclear, although "Okinawa" (Okinawan: Uchinaa) as a term was used in Okinawa. There was also a divine woman named "Uchinaa" in the book "Omoro Sōshi", a compilation of ancient poems and songs from Okinawa Island.