The name Rihanna is a girl's name meaning "sweet basil". Rihanna and is often added to lists like Musician Baby Names and discussed in our forums with posts like "Girls Makeover - Two Middles".
From the experts:
Rihanna, the name of the Barbados-born singer, whose birth name was Robyn Rihanna, attracted a fair number of parents for several years, but has now declined to Number 830. It has also generated several spelling variations.