There are multiple origins and meanings for the name Nina:
1. Hebrew name (נִינָה) meaning - "great granddaughter, great grandchild". The birth of great granddaughters with living great-grandparents in ancient times was a very rare phenomenon and in such cases the word great-granddaughter became a personal name.
2. Spanish (niña) meaning - "brave girl; wench"
3. Hindi given name (नीना) meaning - "slander; beautified, decorate"
4. Georgian (ნინა) meaning - "youth". The name of Jerusalem Patriarch Juvenal`s niece, marked the beginning of Christianity in Georgia.
5. Sumerian "mistress"
6. Shortened form of the given name Antonina
7. Native American "mighty".