Previously reserved for Ernie's companion on Sesame Street, Bert may find new life as a girl's name amid the rising trend of boyish nicknames for girls. With its short, spunky style, Bert fits alongside other vintage picks like Max and Lou.

Short and simple Ty could work as an alternative to Kai or Sky, or as a short form of Tyler/Tyla or Tyra.

Freddy is a quintessential boys name across the pond, but with tomboy nicknames like Charlie and Leni rising for girls -- Freddy may very well make a splash for girls next!

Ties to the unfortunate Mama are now unraveling, leaving Cass or Cassie to stand on its own as a fresher sounding Cathy or Kate. With gender-neutral names abound and the growing trend of boyish nicknames for girls, Cass may be on the up and up.

Bernie is an old school unisex nickname name, on the order of Bobbie or Willie. But with Billie and her tomboyish crew coming back, it's time to get Bernie on your radar! Bernie has a certain vintage charm and is boosted by the funky clunky Bernadette long form.

An early and still quintessentially gender-neutral name, now supplanted by thousands of fresher options. Hasn't been recorded as a given name since 1991.

One of the original cool, sleek gender neutral names, but it's since lost that edge to hits like Leni and Teddy. Today's Teri would probably be Tess or Tessa.

Gussie fits the growing trend of boyish nicknames for girls - alongside Charlie and Frankie. But Gussie is a bit fussy — try Gus.

Similar in style to Teddy, Frankie, Leni, and Murphy, Waldi is both a German and Dutch short form of names including the walt element. such as Waltraud or Walda, or an English diminutive of surname-style name, Walden. Predominantly used as a masculine name, it is a unisex name in Germany.

A cutesy short form of Jordan that's never been overly popular. With boyish nicknames for girls - a la Joey and Scottie - rising, Jordie may have her chance to shine.

Can Ernie shed the rubber ducky association and make its way onto the vintage revivals list? With the growing wave of boyish nicknames for girls — a la Billie and Scottie — Ernie may strike a different note.

A unisex nickname style name, similar in sound and feel to Andie, Candy, Indy, or Danny. The -i ending turns boyish Johnny into a tomboy nickname.

Briefly cool in the 1950s, but now gone the way of Ricki and Nikki. More contemporary: Mikie or Mikey.

Roberta and Robert may be so far out they're... still out, but Robbi might make one of the trendy new boyish nicknames for girls a la Leni and Scottie.

A nickname style name, Neely could derive from the strong sounding Cornelia, as a playful alternative to Nelly from Eleanor and Helena, or as a variation of the Scottish surname McNeilly, with the cool meaning "son of the poet".

For boys, this name calls to mind old-school detective Perry Mason. But peppy Perri is coming around as part of a group of boyish nicknames for girls - along with favorites like Leni and Charlie.

A nickname style name, Neelie could derive from the strong sounding Cornelia, as a playful alternative to Nellie from Eleanor and Helena, or as a variation of the Scottish surname McNeilly, with the cool meaning "son of the poet".

Traditionally a diminutive of Martin or Martina, Mart fits within the rising trend of boyish nicknames for girls. Though many minds may go to "mini mart" or "shopping mart" so Martie is preferable.

With echoes of Marty McFly, Martie is a charming retro nickname name which might derive from Martina, Martha, or even Marceline or Matilda. Part of the growing trend of boyish names for girls, its vintage, approachable feel gives it standout appeal alongside similar picks like Scottie and Frankie.

Roberta and Robert may be so far out they're...still out, but Robby might make one of the trendy new boyish nicknames for girls a la Scottie and Charlie.