Freya has long been popular in the U.K. but has only taken off in the US in the last decade, along with the entire category of mythological names. Derived from the Old Norse name Freyja, meaning "Lady, noble woman", Freya is the name of the Norse goddess of love, beauty, and fertility.

Hugo, the Latin form of Hugh, has more heft and energy than the original -- and of course we love names that end (or begin, for that matter) with an o. This one is especially appealing because it's backed up by lots of solid history and European style.

Mia is an appealingly unfussy multicultural name that has enjoyed a meteoric rise up the charts and is now firmly among the ten top girl names. Mia has surpassed its mother name Maria as the Number 1 girls' name starting with M.

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."

This ancient name, also spelled Caspar, is finally shedding its ghostly image and moving into the 21st century. Popular in the Netherlands and Scandinavia, where it's sometimes shortened to Cas, Casper could ride the style coattails of cousin Jasper.

Fairly popular a hundred years ago but out of the US charts since 1978, the quirky yet edgy Roscoe feels very much in step with the trending o-ending boy names popular now, such as Milo, Hugo, and Otto. A Top 1000 choice in the UK (albeit near the latter end), it could make a cool alternative to Ross, Russell, Robert, and Ronan.

Hallie -- it rhymes with alley and is not to be confused with Halle or Hailey or Holly -- is one of those comfy nicknamish names that are in favor in these complicated times.

One of the flower names, used occasionally in Britain (where it's pronounced DAY-lee-a). It seems to have recovered from what was perceived as a slightly affected la-di-dah air. The flower was named in honor of the pioneering Swedish botanist Andreas Dahl, which means dale.

Birdie was until recently a middle-aged Ladies' Club member wearing a bird-decorated hat --but now it's just the kind of vintage nickname (think Hattie, Josie, Mamie, Millie) that's coming back into style in a big way. Actress Busy Philipps named her baby Birdie (inspired by First Lady Lady Bird Johnson), as did soap star Maura West.

A classic in its native Scandinavia, Axel has a cool rock 'n' roll flavor in the US, thanks to Guns N' Roses' Axl Rose (born William). With its distinctive letter 'x', it has an effortlessly cool vibe about it, and is currently growing in popularity.

Friendly and rugged at the same time, Anders is a Scandinavian form of the Andrew and Andreas family, used across Norway, Denmark, Sweden, and in the US. Consistently in the American Top 1000 since 2010, a recent year saw it given to around 300 boys.

Liv combines the succinct charm of a nickname—people might assume it's short for Olivia—with the solidity of being a classic stand-alone Scandinavian name with a life-force meaning. It was brought into the public eye (in the English speaking world that is) due to the fame of actress and Aerosmith daughter Liv Tyler.

A strong Greek name with pan-European charm, Petra is a relatively recent feminization of Peter, though it relates back to an incredible ancient city in Jordan that was rediscovered in the early nineteenth century.

Lars is a perfect candidate for a cross-cultural passport: it has been heard often enough here to sound familiar and friendly, yet retains the charisma of a charming foreigner.

Rugged and tough, Anderson shot up quite a bit on the pop list in the 2000's, no doubt in large part due to the prominence of white-haired cable newsman Anderson Coopers, more recently, it has featured in the US Top 400, given to 943 boys in the latest count.

Pippi may be cute but isn't very practical. In addition to being forever Pippi Longstocking, there is that variant pee-pee spelling to consider. Try Pippa instead.

Most American parents would choose to use the more commonly seen variant, Axel, but .this form is preferred in Denmark and Norway, and also ranks in the French Top 400.

Digby is a place-name in Lincolnshire turned surname turned quirky first name that is starting to get some attention. In fact, it ranked in the UK Top 1000 in a recent year where it fits in with the likes of Barnaby, Rupert, and Wilbur.

The surname name Jenson is in the British Top 100 thanks to champion race car driver Jenson Button. Jenson might be an honorific for an ancestral John, the English form of Jens or Johannes, or even Jen.

A compact yet impactful name, Taavi is an international variation of the Biblical classic David, notably used in Estonia and Finland. Estonian prime minister Taavi Rõivas was one bearer of the name.