See the popularity graph below for the name Theo? It's been heading straight uphill since 2010, when it hopped back onto the Top 1000 after a 60+ year absence.

Eva is a simple, classic Hebrew name for girls that recently slipped out of the US Top 100 for the first time in more than a decade. Pronounced either like her more popular sister Ava or less popular sister Eve, Eva is one of the elite group of girl names that mean life.

Cleo, one of the few girls' names to boast the cool-yet-lively o ending, is of course short for Cleopatra, the name of one of the most powerful women in history.

An ancient tree that figures in literature from Shakespeare to Harry Potter and is believed to possess magical powers, Willow is a lovely name, as graceful as its inspiration.

Poppy, unlike most floral names which are sweet and feminine, has a lot of spunk. Long popular throughout the rest of the English-speaking world, Poppy is finally starting to rise toward the top in the US, where it entered the Top 1000 for the first time in 2016.

Charlie derives, of course, from the classic name Charles which, in turn, comes from a German word meaning "free man." Charles became very popular in France during the Middle Ages due to the fame of Charles the Great, also known as Charlemagne. Charley is an alternate spelling.

Fletcher is a common surname with a touch of quirkiness; it definitely fits into the So Far Out It's In category--and moving further in all the time along with other occupational names from Parker to Forester.

Aria is a multi-cultural name with two extremely popular versions: this more word-like one along with Arya, the spelling used for the feisty young heroine of Game of Thrones. There were about 6400 baby girls named Aria in the US last year alog with 2400 named Arya, which counted together places the name in the Top 10.

Scarlett Johansson is doing more for this sparky southern name than Scarlett O'Hara ever did. Since the turn of the 21st century, Scarlett has gone from an obscure literary name to one of the most popular girls' names starting with S, right after longtime favorites Sophia and Sofia.

Sweet and stylish, with a sporty, energetic undertone, Everly is a name that ticks lots of boxes.

One of many R- boys’ names that started as a nickname for a redhead, Russell had a measure of popularity from the early twentieth century through the 1950s. But it's now lost much of its color -- except for a few dynamic bearers, actors Russell Crowe and Russell Brand and sports stars Russell Westbrook and Russell Wilson.

Wren, a lilting songbird name, could be the next Robin. Wren entered the Top 1000 for the first time in 2012 and is among the new wave of popular English names for girls.

Percy is an adorable old name that is finally shedding its pampered Little Lord Fauntleroy image in this new era of boys with soft yet traditionally male names like Jasper and Elijah. Originating as an aristocratic Norman name, Percy became fairly widespread in England--and to some extent in the US--as an offshoot of the fame of the poet Percy Bysshe Shelley.

Ellie first took off in the UK—yes, in this nickname form—and this warm and friendly name has also become hugely popular here. In 2011, Ellie entered the US Top 100 girl names for the first time and has remained near the top of the charts ever since.

Rue has gone from Golden Girls actress to Hunger Games heroine to a fresh alternative to beloved middle name Rose. This botanical name is also a coincidental double word name, meaning "regret" in English and "street" in French. Despite these unfortunate secondary meanings, Rue has real potential to be one of the most popular new middle names for girls.

Piper is a bright, musical name that entered the list in 1999, one year after the debut of the TV series Charmed, which featured a Piper, and it's been a consistent riser since. Piper Kerman is the memoirist whose prison experiences provided the basis for the hit Netflix series Orange is the New Black.

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.

Phineas is the English variation of Phinehas, a Hebrew name likely derived from the Egyptian name Pa-nehasi. Pa-nehasi, meaning "the Nubian" can also be translated as "the bronze-colored one." The Egyptians distinguished themselves from their Nubian neighbors through differences in skin tone.

Juno is an ancient name that feels as fresh as if it had been minted, well, not yesterday, but in 2007. Since the release of the popular indie film Juno, this lively but strong Roman goddess name has held new potential as a baby name. Currently in the UK Top 500 and used in The Netherlands too, Juno is on the rise in the US - and is 15 times more popular than it was before the release of the film.

Indigo is one of the most appealing and evocative of the new generation of color names. Color names have joined flower and jewel names -- in a big way -- and Indigo, a deep blue-purple dye from plants native to India, is particularly striking for both girls and boys. Indigo is the name of a character in the Ntozake Shange novel Sassafrass, Cypress & Indigo, and was used for his daughter by Lou Diamond Phillips.