One of the most romantic of appellations, Caspian is a geographical name referring to the large salty sea between Asia and Europe. It's also the name of the hero of C.S. Lewis's beloved Chronicles of Narnia, Prince Caspian.

Sadie started as a nickname for Sarah, but their images couldn't be more disparate. Where Sarah is serious and sweet, Sadie is full of sass and fun.

Noah is nearly a patriarch of popular baby names at this point, going from Old Testament graybeard to Top 10 name in 2009, hitting Number 1 in 2013, and now settled into second place in the US for the past eight years.

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.

Otto is cool again. Long a quintessential Old Man Name, Otto has been promoted to trending darling of adventurous baby namers.

Oscar is one of the most stylish Old Man Names of our era. While it's softened slightly in popularity over the past 20 years, that may be considered a very good thing.

Kai is an internationally flexible name with many possible origins and meanings, growing in popularity in the US and a diverse range of European countries.

Declan is the Anglicized form of the Irish name Deaglán. St. Declan was one of the first missionaries to bring Christianity to Ireland, preceding St. Patrick. Originally from Wales, he founded the monastery of Ardmore in Ireland.

Astrid has been a Scandinavian royal name since the tenth century, and many people associated it with the Swedish author of the Pippi Longstocking stories, Astrid Lindgren. Astrid is derived from the name Ástríðr, which is made up of the Old Norse elements that mean "god" and "beautiful."

Caleb is an attractive Old Testament name that has been in the US Top 100 for nearly three decades now. Consistently popular but never too popular, Caleb feels more like a classic than a momentary trend.

Elise is one of those golden names that stylish but not TOO popular. Its appeal is due in large part to its French flair and to the love for El-names in general.

Actor Kit Harington, aka the dreamy Jon Snow on Game of Thrones, has given this nickname-name new style and appeal for boys. Actress Jodie Foster used it for her son back in the 2000s, while actor Kit Connor of Heartstopper fame may have introduced it to a wider audience.

The related Lucas and Luke are both hugely popular boy names in the US and internationally, and now Luca has joined them on boys' popularity lists around the world.

Nico is one of the great nickname names, full of charm, energy and effortless cool -- a neo Nick.

Stella is a name with star quality and sparkle, that manages to sound both ethereal and earthy. Celestial but not otherworldly, it lands somewhere between the popular Ella and bold Seraphina.

Florence is back, returning to the US Top 1000 girl names in 2017 after a nearly 40 year absence. Other English-speaking countries have been quicker to welcome Florence back into fashion.

Alexander has been in a Top 25 boys' name in the US for 30 years now. But namers are still attracted to its imposing historic pedigree.

Victor is one of the earliest Christian names, borne (as Vittorio) by several saints and popes, symbolizing Christ's victory over death. It has been quietly in the Top 200 since 1880, but just recently has taken on a cool edge by fashionable parents in London and seems ripe for a similar reevaluation here too.

Natalie — a Franco-Russian name — became Americanized years ago and is one of those surprising names that's always ranked among the girls' Top 1000 names in the US.

Cassius, a Shakespearean name rooted in antiquity, is trending in a major way. It's one of a raft of Cas-starting names for both boys and girls, including Caspian, Cassian, and Cassia, that are enjoying a new moiment in the sun.