Penelope is an unlikely 21st century baby name success story. Off the Top 1000 for 25 years, Penelope jumped back on in 2001 and has been heading uphill ever since, propelled by the trend for mythological names, Spanish actress Penelope Cruz, and some high-profile celebrity babies.

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.

Magical and earthy, sophisticated but off-beat, Persephone appears as the daughter of Zeus by Demeter in Greek mythology. After she was kidnapped by Hades to be Queen of the Underworld, it was decreed by Zeus that she would spend six months of the year with her mother, allowing crops to grow, and six in mourning, thus accounting for the change of seasons. As such, she is both the goddess of the Underworld and of Spring.

Pandora has occasionally been used by the British gentry (for girls with brothers who might be called Peregrine) and is now starting to be heard in the US too: It was given to 34 baby girls last year.

This simple, elegant name offers something for many kinds of parents, from writers and history buffs to photographers to Pennsylvania dwellers. Most famous bearers are comedian Penn Jillette and Gossip Girl hottie Penn Badgley, both of whom were given this distinctive name at birth. Long obscure, Penn seems destined for greater usage.

A sweet, nostalgic nosegay kind of name, Posy has been long fashionable in England, a country of gardeners, but this pretty bouquet-of-flowers name is still rarely heard in the US, though it could be seen as a more unusual possible alternative to Rosy or Josie.

With its bubbly sounds and stylish feel, Pepper joins a small but distinctive group of names inspired by the spice rack: Saffron, Juniper, Cassia, Sage, Ginger, and Rosemary. Enough like Pippa, Piper and Penelope that it feels usable, Pepper has appeared every year in the US stats since the 60s.

Pixie is a cute -- quite possibly too cute -- name that suddenly feels possible thanks to the craze for names that contain the letter x. Though its origin may be uncertain, a pixie is internationally recognized as a sprite or fairy: tiny, sometimes green, usually pointy-eared.

Super-sweet name that was the title of a Broadway play -- but best known as a type of apple. The Dutch variation is Pepijn is finding some popularity in that country, where short nickname names are stylish.

British-born novelist Plum Sykes has taken this rich, fruity name out of the produce section and put it into the baby name basket. It's more appealing than Apple, more presentable than Peaches. The French equivalent, Prune, is very fashionable there but would not fly with English speakers.

Puck was Shakespeare's mischievous pixie who'a had a few television incarnations in more recent years. A popular name in The Netherlands but nowhere else, from what we can tell.

Peridot is the gem of the month of August, a vibrant green mineral, said to be good for helping people put the past behind them, and an interesting, undiscovered jewel name. It was regarded in ancient times as the symbol of the sun.

A recently entered name on the roster, Poet was used for her daughter by Soleil Moon (Punky Brewster) Frye, who obviously appreciates the advantages of an unusual name. This is a possible middle name choice for verse-loving parents who want to skip specifics like Auden or Poe or Keats or Tennyson and go with the generic.

A handful of baby girls were named Poem in the US in the most recent year, along with Poet and Poetry. But of course, these word names can work for boys too.

The Roman god of the underworld, the former ninth planet, a cartoon dog...but not a baby.

Castor's twin in the constellation Gemini. That final x makes this name modern and cool.

Promise is one of those word names with an uplifting meaning that is making inroads as a girls' name, like sisters Dream and Serenity. How promising is Promise as a first name? Our try at cleverness illustrates perhaps the biggest problem with naming your baby girl Promise: It will be difficult for people to resist making bad puns on the name. We promise (argh) you'll be tired of hearing them well before your baby Promise's first birthday.

In France, pronounced PRO-spare, Prosper is a fairly common name; here it presents a worthy aspirational message for a child.

The name Persia derives from Avestan Parsa, the name of the Indo-European nomadic people who migrated into southern Iran in about 1000 BCE. Persis or Persea, the feminine form of Perseus, feel more namelike.

Occasionally heard in England, rarely here.