Instagram ads for one brand are touting a style known as “power casual.” Other retailers are calling it “business comfort” or “workleisure.” Heels are dropping lower or disappearing altogether, pants are getting “elasticized,” and Silicon Valley executives are throwing graphic T-shirts under blazers to smuggle a version of self-expression into a board meeting.

Welcome to the new world — and marketing-speak — of work clothing.

Retailers that once trafficked in solidly reliable dresses are scrambling to cater to the new demands of the hybrid workweek. They want to tempt a dazed customer base that is returning to offices and in-person meetings with trends like “the casualization of the lower half” and fabrications that look like 2019-era professional garb while offering “secret comfort.” (The secret is usually spandex.)

In fact, the retail industry has so fully embraced softer and stretchier styles that some professionals say they have had to turn to used clothing sites to find appropriately formal clothing for law firms and government jobs.

“There’s very little separation now between where you work and where you live,” said Sarah LaFleur, chief executive of M.M.LaFleur, a women’s clothing brand that is trying to be known for more than office apparel. “We’re seeing the same trend happening in clothing.”

The shift isn’t just a matter of taste — it has ramifications for mass apparel, a significant segment of the economy, and the physical face of retail, which is the second-biggest private employer in the United States. Revenue from women’s apparel in the United States was $132.7 billion in 2021, up 7 percent from 2019, while sales of men’s apparel rose 11 percent from 2019 to $76.5 billion, according to data from the NPD Group, a market research firm.

As more of that revenue shifts into denim, sneakers and the like, particularly for women, retailers must keep pace. Already, NPD found that dress footwear sales declined 34 percent last year from 2019 while men’s tailored clothing for the 12 months that ended in February was down 20 percent from two years earlier. Mass chains like Banana Republic and J. Crew have been shrinking their store counts while adjusting their assortments.

Meanwhile, Lululemon now has annual sales that exceed the Gap and Banana Republic brands combined and aims to double that in the next five years. Lululemon and Athleta, which is owned by Gap Inc., both promote work clothes on their websites. Customers are willing to pay for comfort: Gap said on a September call that across its brands, the average unit retail price, a measure of what a garment sells for, was $12 at Old Navy, $40 at Banana Republic and $60 at Athleta.

How people dress for work can be a reflection of the labor market. Economic downturns, like the collapse of the dot-com boom or the 2008 financial crisis, have often prompted returns to dressier clothing as a form of risk aversion — people want to show the boss they’re making an effort. In the current climate, when the unemployment rate has fallen to the lowest level since the pandemic took hold, employees might think: My employer is lucky to have me, so why should I wear pants that zip?

Additionally, many have conflicted feelings around in-person work. Future Forum, a research group backed by Slack, recently found that 34 percent of office workers were physically back full time and that work-related stress and anxiety were at the worst level since the group began surveying 10,000 office workers in the summer of 2020.

The pandemic caused so much psychological distress for Americans that “the last thing bosses want to pay attention to” is whether an employee’s clothing is appropriate for work, said Jaehee Jung, a professor of fashion and apparel studies at the University of Delaware. “People are also endorsing more casual looks for their employees so that they feel more content and happy,” she added.

Work is confusing. Clothes are, too.

M.M.LaFleur’s stores, including its Bryant Park location in Manhattan, were booked up in March with women seeking personal styling appointments after a virtually “dead” January, Ms. LaFleur said.

The retailer, which took a financial hit in 2020, has been running ads on social media that lean into the workwear vocabulary du jour of “power casual” garb, with blazerlike cardigans, and others that proclaim, “Your leggings got a promotion.” Ms. LaFleur said the power casual portions of its site were generating triple the sales of those promoting more traditional dresses. Before the pandemic, dresses made up about one-third of the company’s sales, but that has dropped below 20 percent.

Retailers have to figure out what will make people happy at work — a tall order in a nation of confused employees — or at least try to convince them that leggings will help make their days better.

“It’s really the retailers responding to market demand,” Ms. Jung said. “Companies are reducing their products that are geared toward formal attire and business wear.”

Nordstrom, which has hundreds of full-price and Rack locations around the country, saw a 152 percent increase in searches on its website for the term “workwear” in February, said Shea Jensen, the retailer’s general merchandise manager for men’s and women’s apparel.

The site has used terms like “workleisure” and has a section called “New Work Dress Codes.” From there, shoppers can navigate to “WFH Reset” for “video-call-approved styles.” There’s also “office ready,” which promises to “connect the dots between feel-good and professional.”

“We saw radical swings in work attire through Covid as people were dressing for the keyboard up, as we like to say, and now as they return to the office, there’s a really exciting enthusiasm about head-to-toe dressing again,” Ms. Jensen said.

Nordstrom, she said, believes that “the return to more structure is definitely on the horizon” — a trend that already has some customers turning to crisp cotton shirts, colorful power suits, structured blazers and trousers. But the guiding term for most is “versatility” as many customers return to offices only a few days a week or balance in-person meetings with remote work. Denim, once relegated to casual Fridays, is “really having a moment,” Ms. Jensen said, while other garments have “elasticized.”

“It wouldn’t be strange to see a really hip elastic-waist fleece jogger with a really incredible blazer, maybe with a sharp white cotton shirt under it,” she said. “There’s more license across the items in your closet.”

Elastic-waist fleece joggers — pants that balloon in the thighs and are generally advertised as ideal for weekend coffee runs — plus a blazer? To the office?

Those are the sorts of questions that have left people like Rebecca Sherman, a product management director who lives outside Philadelphia, scratching their heads. Ms. Sherman, 37, has not worked in an office since 2019. Before, she said, she dutifully purchased new business casual clothes every season. Now she’s largely working remotely, which caused some wardrobe consternation as she prepared for an in-person meeting with her colleagues in Los Angeles. In the design and digital world specifically, people tend to want to look stylish but casual at the same time, Ms. Sherman said.

“I looked at Refinery29, I looked at Vogue, I’m in some working moms Facebook groups, but to be honest, I don’t really know where to look for trying to figure out what’s actually in style,” she said. “I have a closet full of perfectly nice clothes that I haven’t worn in three years, and I could probably put together a nice outfit.” But, she added, “I won’t look 2022 — I’ll probably look 2015.”

In recent American history, business attire has gone through cycles of formality, from the suits and A-line dresses of “Mad Men” to yesteryear’s J. Crew aesthetic of skinny black pants and silk blouses or slacks and button-downs. And even shifts to more casual styles have tended to operate within guardrails: trousers rather than jeans, blouses versus T-shirts. When it comes to job-hunting, applicants and college graduates have long been instructed to have “interview suits” or similar garments at the ready.

But never before had the modern office been so upended as it has been in the past two years. The length and scale of the disruption — particularly as work schedules are still being established — are likely to set a new normal for the foreseeable future, experts say.

“People are changing their perceptions of what work clothes should look like,” Ms. Jung said. “It can be hard to define when cultural shifts are happening, but I think this is happening now.”

So, what are people wearing?

J.T. O’Donnell, a former human-resources executive and founder of the career coaching platform Work It Daily, said she would not recommend that job applicants or recent graduates automatically buy interview suits these days. While that may work for some industries, like banking and consulting, she said, job candidates should research potential employers on social media to get a sense of how people at the company dress, then “dress slightly higher than what their proclaimed style is.”

“It can be very easy to say right now that they’re lucky to even have me walk through the door, so I just don’t care about my appearance right now,” Ms. O’Donnell said. But “you do want to not be wrinkly, have stuff tucked in, look like you made an effort.” She advises job hunters to wear clothing suitable for visiting their grandmothers.

Victoria Hitchcock, a stylist in the San Francisco Bay Area who also helps clients with personal branding and “lifestyle transformation,” said she had been seeing high-powered female clients return to suits, though they are pursuing more casual materials like “silk crepe fabric,” flare legs and higher waists and sometimes pairing them with loafers or sneakers.

She said she had been fielding daily requests from executives to bridge the gap between “pre-Covid norms and post-Covid ‘woke’ expression.” In practice, that translates into graphic T-shirts, with phrases like “Babes supporting babes” and “A founder — not a female founder,” paired with pantsuits or blazers.

After a two-year hiatus, men and women “want to have that kind of message that I’ve been gone, I’ve been away, I’ve been somewhat tuned out and working on myself and here I am,” Ms. Hitchcock said.

Stitch Fix, the e-commerce clothing and personal styling company, has been referring to the latest workwear trend as “business comfort.” Eighty percent of its customers who are returning to offices this spring are choosing that style over more traditional workwear, according to a survey of about 1,300 of its clients in March. Stitch Fix recently published a blog post describing the “continued casualization of the ‘lower half,’” a carry-over from the Zoom era.

“Women are asking more and more for pants that have elastication on the waistband,” said Loretta Choy, Stitch Fix’s chief merchandising officer. “So it’s really goodbye to buttons and zippers and everybody wanting to have this easy pull-on pant.” She added that women were reaching out to the company for help after spending so much time focused on dressing from the waist up.

Pity the Ann Taylor loyalist, left behind.

The trend toward more casual clothing has left a significant swath of shoppers in the dust — namely women who still need to wear traditional professional attire to jobs in fields like law and government, and who are in-person five days a week. Men can still find dress shirts and ties in stores and certainly online. But as major retailers and smaller labels embrace daytime dresses and new fabrics, the shift has frustrated customers like Abra Belke, a lawyer, and readers of her website, Capitol Hill Style.

“You have retailers and designers that professional women relied upon, both large and small, to produce professional dresses, jackets, trousers, suits, who are now selling jersey knit pieces and leggings, and little sundresses and graphic colorful prints,” said Ms. Belke, 39, who lived for years in Washington D.C., and now splits her time between Spokane, Wash., and Helena, Mont.

“When I go to Bloomingdale’s website and click on the dresses-for-work tab,” she added, “the first five are sundresses, and it’s like, ‘Where do you guys work?’”

She said she had been “inundated” with emails from readers of her site who were baffled about the new direction of once-favored brands, especially as many people seek the same garments in new sizes after a long two years. She has had to turn to used clothing sites like Poshmark to find work-appropriate clothing and has seen readers similarly turn to thrift shops and buy-sell-trade groups on Facebook.

“Most of Ann Taylor’s new suits for spring are linen blend, and my response is just, ‘Where am I wearing that?’” Ms. Belke said. “This isn’t 1925. I’m not headed to a party at Jay Gatsby’s house.”

“I’m working for an industry dominated by boomers and Gen X-ers,” she said. “They’re not going to change their beliefs on what constitutes professional dress just because we all wore spandex for the last two years.”

But all hope is not lost. Ms. Belke said that while her workplace still expected a certain level of formality, some concessions had been made in shoes, and that she was now able to wear flat shoes instead of heels.

Some experts have speculated that the pandemic may have killed off the popularity of “commuter shoes” and extra high heels stashed under women’s desks. “Not surprisingly, people are deciding not to wear them anymore,” said Sasha Skoda, the head of women’s merchandising for the RealReal, the luxury resale site. While the site has seen a surge in heels consignment, demand for low heels, wedges and ballet flats has soared, she said.

Ultimately, brands anticipate that more comfortable work garb will bring employees some peace of mind — a Xanax for the closet, if you will.

“Going back to in-person interactions can be anxiety-inducing enough,” Ms. LaFleur said. “So let the clothes be the least stressful thing.”