Image copyright London Modest Fashion Week/Haute-Elan.com

Ankle-grazing hemlines, floaty sleeves and necklines which stop at the, well, neck. Modest dressing is having its day and putting cleavages and bare thighs under wraps.

Farrah Storr, editor of the sexually-liberated magazine, Cosmopolitan, has written in the Times about why, at 38, she has decided to cover up.

Age, she says, has something to do with it, as does body-shape (my hips are becoming "padded, my backside "cushiony") but it's also about her reconnecting with her Pakistani heritage.

In the office, she settles on tuxedo shirts and white trainers - "a sort of sexless template for my work persona", she writes.

Others at the top of their game are also dressing modestly.

Adele delights the fashion world in custom-made dresses and haute couture, but rarely bares her arms or displays more than an ankle.

Image copyright PA/Rex Image caption In 2003, Victoria Beckham's dress was low-cut with a hemline just below the knee when she accompanied her husband, David, to Buckingham Palace to pick up an OBE; this year, her hemline was down to her ankles when she picked up her own

And Victoria Beckham, once associated with Little Black Dresses and those silk green hotpants on the catwalk, is now more likely to be seen in long, loose dresses with only a smidgen of flesh on show.

But are these women opting for a more flowing silhouette because of their age and shape, or is modest dressing a new fashion trend?

Nazmin Alim is creative director at Aab, which has been making modest wear for 10 years.

She says the idea of dressing modestly has always been around but over the last couple years, the fast-growing population of young Muslim women has pushed the concept on social media.

They have spending power, influence and don't want to compromise faith and fashion - so the market has taken note, she says. On Instagram, there are hundreds of thousands of images with the hashtag #modestfashion.

Image copyright Getty Images Image caption Adele lit up the stage at Wembley Stadium, but kept bare flesh to a minimum

Nazmin recalls looking for a long skirt years ago, but only finding a pencil skirt with a big slit.

Now, she says, Aab is offering an "alternative fashion choice". These are clothes not just for Muslim women but other women who feel more comfortable with their arms and legs covered, she says.

The recurring theme around modest fashion is that a definition is difficult to find, and not altogether necessary.

Romanna Bint-Abubaker, who was behind London's first Modest Fashion Week in February, says she believes modesty has so many forms and is for everyone.

"We provide choices and alternatives. We're not dictating what that modesty should look like," she says.

Women do not need to dress in a way to attract attention these days, she says, they have character and power, and it's their personality that's doing the attracting.

Her company, Haute Elan, which curates collections of modest clothing for its London store and website sells mainly to women in their 20s from the UK, US and Middle East.

When choosing pieces, style is the number one priority - comfort and modesty, a joint second, she says.

Image copyright Aab Image caption Aab designs with comfort and design in mind, including length, movement, sleeves and interchangeable pieces

So if modesty lacks a definition, where do sellers draw the line?

With summer holidays around the corner, Romanna says bikinis are off their radar, but they might stock a swimsuit with a skirt covering the thighs.

And remember Nigella Lawson on the beach in a burkini? Romanna says the suit that covers the whole body except the face, hands and feet sells well to women who aren't Muslim but might be slightly older or larger.

Mehreen Baig, a 27 year-old British Pakistani, says she worries about labelling clothing " modest". That implies everything else is immodest, she points out.

"Clothing is all about self-expression, and that's different for every person. What I wear depends on what day it is, my mood and where I'm going." Today, on a dress-down at work day, she's wearing leggings, flip-flops and a baggy top.

Not exactly modest, she says. But her big circle of Asian, Muslim friends, who wear headscarves, might seek out designers to find clothing to match their hijabs.

"Girls who want to cover up have got somewhere to go to now where they can feel fashionable and cover up. That's a beautiful thing," she says.