Leo is a strong-yet-friendly name that was common among the Romans, used for fourteen popes, and is now at its highest point ever in the US thanks in part to Leonardo "Leo" DiCaprio.

Helena is one of those classic names that just misses making the US Top 1000 girl names for its entire history, falling off for a single year in 1992. Since then it's been drifting lazily up the charts, and makes a perfect choice if you want a name that both fits in and stands out.

Credit the award-winning single-named British singer for taking the girls’ name Adele from a quiet semi-retirement back into currency. Adele reentered the US Top 1000 popular baby names in 2011 and has remained there ever since.

An underused Biblical name, probably because it's so tightly identified with the Queen of gospel singers, Mahalia Jackson. Other variations include Mahalah, Mahayla, Mahila, Mahilia, Mehalia, Mahali, and Mahalya.

The feminine form of Helios or Helio is occasionally heard in Spain and Portugal. In Greek mythology, Helia is one of the Heliades, daughters of the sun god Helios by Clymene the Oceanid.