In the intimate world of lingerie, naughty words are nothing new, but few cause noses to wrinkle more than “girdle.” Like the corset, it was born out of necessity to help women fit into the fashions of the times, yet no one spoke of it outside the boudoir. All the uncomfortable tugging was something women grinned and bore. Cut to 2007, when everyone from Oprah to Beyonc to Gwyneth Paltrowcan’t stop touting her support undergarments to the world. To be sure, social mores have changed, but so has the technology behind these pieces, now commonly called shapewear.

A closetful of brands, including Spanx, Cass and Co. and Sassybax, have transformed the support scene by enabling anyone to wear clingy or sheer clothes with as much confidence as a celebrity strutting down the red carpet.

Not surprisingly, several of the newest lines were founded by fashion-loving women who weren’t satisfied by the pieces on the market. And it’s not necessarily about weight or size, although the slimming effects are obviously a selling point.

Spanx founder Sara Blakely, a size-4 former copier saleswoman from Atlanta, created her first prototype after she was forced to cut the feet off a pair of control-top pantyhose so she had something to wear under white pants. “Designers are selling us clothes with nothing to wear under them,” she says. “If you love clothes, you gotta have your Spanx because they make the clothes look better.” Blakely says her pieces also make women “look and feel a size smaller.”

What woman, especially a new mom, wouldn’t want that? Cass and Co. founder Susan Ledyard, a former dancer, got into the shapewear business after giving birth. “Having children and loving skinny, low-rise pants has put us all back into shapewear,” she says. Indeed, new moms Mariska Hargitay, Gwen Stefani and Cate Blanchett have all gone on the record in support of Spanx. And Gwyneth Paltrow says she wore two girdles – at the same time – to hold it all in after Apple was born.

Their enemy: the unseemly roll of flesh just above the waistband, commonly known as the “muffin top.”

“I couldn’t find anything that was long enough to smooth out that bump,” Ledyard recalls. At the same time, she needed a top piece that would eliminate or replace the lines that came from bra straps. Ledyard came up with a seamless bra top called the Invisibella to cover all the problem areas. Last year, Cass and Co. introduced pieces to address the bottom half of the body as well.

But it’s not just women with less-than-perfect figures who swear by shapewear. “I have to tell you, Spanx has changed my life – I can’t live without them,” said pin-thin actress Samaire Armstrong at a recent Rodeo Drive fete. Armstrong was wearing a pair underneath her crimson Ferragamo sheath. There were no apparent bulges, but she didn’t need much help to begin with. So what gives?

“I’ve had clients request Spanx who don’t need them. With these perfect-looking women, you can just slightly see the difference, but it makes them feel more secure when they feel cinched in. It’s a mental thing,” says stylist Danny Flynn.

“Ugly Betty” stars America Ferrera and Ashley Jensen both got a confidence boost from the Spanx they wore under their Golden Globes gowns. “I never go anywhere without them,” Jensen says. “They hold you in, make you thin.”

Such enthusiasm for shapewear could be something actresses are picking up on set, where Spanx and the like are used to slim starlets by up to two sizes. Sharen Davis, costume designer for “Dreamgirls,” reportedly placed bulk orders of Spanx for stars Beyonce, Jennifer Hudson and Aniki Noni Rose to wear during filming. The formerly unfashionable, girdle also played a pivotal role in “The Devil Wears Prada,” whose stars Meryl Streep, Anne Hathaway and Emily Blunt wore Spanx beneath their designer duds.

Given the attention these shapewear lines have gotten in Hollywood, it was perhaps inevitable that celebrity stylists would get in on the act. To wit, in December, Estee Stanley and Cristina Ehrlich launched a line of figure fixers called Premiere Line for Frederick’s of Hollywood. The duo designed strapless bras, butt lifters and tummy flatteners using high-tech silicone and paper-thin stretch fabrics barely detectable beneath even the most revealing clothes.

“What we do for our celebrity clients takes work to make them look so flawless. If women know that it takes help for these ladies to look their best, then they feel like it’s possible for them to look great, too,” says Stanley.

With such solutions available in department stores, specialty stores and online, everyone has access.

“Before the Spanx and breast petals route, I would do all sorts of things with masking tape and electrical tape. I busted out with tricks that drag queens taught me,” says Flynn. “Things are so easy and painless now.”

Chest Pieces

Thanks to exposure on the runways, the red carpet and daytime TV shows like “Oprah,” daring décolletage has made the specialty bra de rigueur.

“A lot of girls are looking for the look popularized by Victoria’s Secret – the well-rounded bosom pushed up under her chin,” says Sonja Winther, president of Chantelle North America. “There’s been a lot of demand for specialty bras.”

As a result, average women have become savvy consumers when it comes to wearing the right bra to plump up, push together or cup the breasts for a form-fitting lift, whether the neckline is Empire, baby doll, strapless, backless or a V-neck halter.

“There’s been a tremendous obsession with celebrities,” says Susan Nethero, chief fit stylist for Intimacy boutiques in Atlanta, Chicago and New York. “We find that a big part of the attraction is what celebs are wearing and whether they’re wearing it right. Women everywhere, including the rich and famous, want the right shape and breast appearance for their formal attire.”

Intimacy’s top-selling specialty brands include La Perla, Lise Charmel, Simone Perele, Aubade and Le Mystere, which offers a cleavage-enhancing demi balconette style with memory foam like that used in Swedish mattresses. “You lie down and it takes your shape,” says Le Mystere chief executive officer Michael Rabinowitz.

Karyn Monget – Bienvenue A Brooklyn

Fifi Chachnil, the Parisian designer known for her glamorous, Fifties-inspired lingerie, is coming to New York, although not to one of its more commercial districts. Rather, she has chosen a second-story, red-brick apartment at 338 Lafayette Avenue in Fort Greene, Brooklyn, that will serve as an intimate, by-appointment-only boutique.

“In the same way tourists view Montmartre as a picture-postcard vision of Paris, Brooklyn has always been my image of New York,” says Chachnil, who intends to decorate the space, set to open in mid-February, to resemble a boudoir. The atelier will be dedicated to made-to-measure pieces such as lingerie-inspired cocktail dresses, corsets and gloves. Prices will run $700 to $4,000 for a dress, $700 for a pair of gloves and about $800 for a waist cincher shapewear. Chachnil’s regular lingerie selection will also be available.

“It’s in line with my desire to create an intimate space and to offer a luxury service,” says Chachnil, who recently closed a streetfront boutique on Rue Cambon in Paris because it lacked intimacy. She’ll travel to New York once a month for fittings, and her local assistant, Edwige Walls, will measure clients and help select fabrics that will then be sent to Paris to be made up.

Chachnil now has two Paris locations, on Rue Saint-Honor and Rue Jean-Jacques Rousseau, and is sold in some 80 stores internationally, with plans to open a London shop next year.

Katya Foreman – Intimate Details

“The right bra is like the perfect man: good-looking, supportive and sure never to let you down.” These words of wisdom, along with matter-of-fact advice and confidence boosters from Rebecca Apsan, owner of New York’s La Petite Coquette, will keep readers engaged in “The Lingerie Handbook,” out last fall from Workman Publishing ($13.95). With 30 years of lingerie experience under her garter belt, including a stint as lingerie consultant to “Sex and the City,” Apsan collaborated with Sarah Stark to put her extensive knowledge into 186 pages of innerwear insights. So if “lingerie is therapy,” toss out those granny panties, dig out those “date night” knickers hiding in the back of your drawer and let loose your inner coquette.

Tara Bonet-Black – A Little Something Extra

La Perla fans have several ways to wear the company’s seductive designs, but dangling a drop of black lace from each earlobe is one of the newest and most eye-catching.

The earrings stand out in a sea of fall accessories from lingerie labels, but they are by no means the only pretty pieces. French designer Vannina Vesperini has created a pink pearl brooch to complement her latest collection. And fellow francophone Elise Anderegg strings necklaces mixing Murano glass, Swarovski crystals and beads.

Her accessories production is up 40 percent over last year, says Anderegg, who also hand-knits mittens trimmed in Chantilly lace. “Initially, I designed pieces to decorate my stand, but buyers kept wanting to place orders.”

Picking up on this retailer demand, Eurovet’s Salon International de la Lingerie, running Feb. 2 to 5 in Paris, will debut a new space dedicated to the burgeoning category, dubbed Spicy Boutique. Among the area’s offerings: cupcake-shaped “bon bon” soaps from Gentry de Paris, L strap’s bejeweled bra straps and a new line of ballet flats and shoes to pair with Sabrina Nadal’s ballerina-inspired lingerie.

Says Chantal Malingray, executive director of Eurovet’s lingerie division: “Designers are latching onto the idea that accessories help create a universe.”