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.

Owen, a resonant Celtic name, has ranked among the Top 100 boys' names in the US for 20 years and is now at its highest point ever.

Grace, a simple and pure virtue name which originally referred to divine grace, is a fashionable classic. In the early 2000s, it seemed headed for the Top 10 but pulled back from the upward trajectory, which you may consider a very good thing.

Melodic and beautiful but with a touch of sass, Calliope is the name of the muse of epic poetry — and perhaps less glamorously, the musical instrument on the merry-go-round. Bold and creative, it debuted in the US Top 1000 in 2016, and in more recent year, IT appeared in the Top 500.

Also spelled as Kalliope — the more traditional Greek transliteration — Calliope means "beautiful voice", making this a musical and poetic choice. It was rarely heard in the US until the 2000s when Calliope "Callie" Torres from the show Grey's Anatomy helped introduce it to a wider audience.

Iconoclasts though we may be, we like Fred, we like Frank, and we like George, which was among the Top 10 from 1830 to 1950, when the number of little Georges started to decline. Solid, strong, royal and saintly, yet friendly and unpretentious, we think that George is in prime position for a comeback, especially since it was chosen by Britain's royal couple.

Jackson is one of those names that's much more popular than you think, coming in near the top of our annual Playground Analysis, which ranks names by grouping all their spellings together. Last year, more than 13,000 baby boys were named Jackson -- along Jaxon, Jaxson, Jaxxon, Jaxen, Jaxyn, Jaxsen, and Jaxsyn -- which counted together makes it the Number 5 boys' name.

Avery is a unisex name that is used four times as often today for girls as for boys. But while Avery's popularity is starting to soften for girls, it continues to get stronger for boys -- in keeping with our finding that gender neutral names are becoming more favored for boys than for girls.

Derek started out as a sophisticated Brit, but the name became so common over the last decades of the twentieth century that it lost much of its English accent, along with its stylish edge. Derek was a Top 100 name in the U.S. for 25 years, from 1970 to 1995, after which it began to decline.

Britney Spears put this old-fashioned surname name back on the map when she chose it as her son Sean's middle name, which the family uses as his first.

Newly fashioned but familiar and with an on-trend, unisex feel, Addison seems like the perfect solution for anyone who can't decide between Madison, Adeline, and Alison.

Meredith is a soft, gentle-sounding name with subtle Welsh roots. Although originally a boys’ name , Meredith is used mainly for girls now.

Harper got its start as a celebrity baby name when Paul Simon chose it for his now-grown son. Since then, other famous parents have followed suit: musician Tim Finn and actor Cecilia Peck both have sons called Harper.

Thatcher is an open and friendly freckle-faced surname, fresher sounding than Tyler or Taylor, that dates back to the days of thatched-roof cottages. It is catching on with modern parents—it reached the US Top 1000 for the first time in 2013.

The girls have Violet and Scarlet and Ruby and Rose, but for the boys there's a much more limited palette of color names. Grey/Gray is one exception, which could make for a soft and evocative—if slightly somber—choice, especially in the middle. Kaitlin Olson and Rob McElhenney named their son Leo Grey.

The Scottish spelling of Isabel has a definite character of her own, the 'o' giving her an extra infusion of strength but also an element of confusion. How do you pronounce that? Answer: Exactly like Isabel or Isabelle.

Bailey — a jaunty surname — was first used for a female TV character in 1978 in the show WKRP in Cincinnaati, then caught on big time. Bailey's still an appealing choice, though, and a celebrity fave. Parents of daughters named Bailey include Scot Baio and Stella McCartney.

Once the most popular month names, April has been overtaken by June (for girls) and August (for boys), as well as the charmingly old-fashioned May. Literary reference: the heroine of the book and movie Revolutionary Road, and there have been Aprils on Parks and Recreation, Glee, and The Vampire Diaries. Trivia note: comedian Ralphie May named his daughter April June May.

Christina, a pretty and feminine, crystal clear classic, may be trending downward, but it's never out of style. Christina's short forms Chris, Christie, and Tina all seem dated—making the royal Christina best used in its full glory.

Ellis, a surname used sparingly as a first in the Wallace/Morris period, sounds new now for girls, as a gender-neutral alternative to Ella or Alice. It debuted in the US Top 1000 for girls in 2015.-- Ellis has always been in the Top 1000 for boys -- and seems to be headed straight up. One of the most popular gender-neutral names, currently there are two baby boys named Ellis for every girl.

A few decades back, this name -- which hardly shows its Irish roots -- evoked a man in a gray flannel suit; now, though still upscale, it's more likely to be attached to a female.