WE live in the age of the girl. That sad truth is inescapable. Gone, it often seems, are the days when anyone would use the word “woman” and expect to be of any cultural significance or relevance. Everywhere you look there are girls. Television brings us the drama series Girlboss, Girls and Our Girl. Cinema has delivered Gone Girl and The Girl With The Dragon Tattoo. One could be forgiven for thinking that a seismic demographic shift has happened and we are in the middle of a girl boom. But of course, most of these girls aren’t female children but, whisper it, adult women.

Nowadays, the word “girl” evokes both what people want to be and what they don’t want to be. “Don’t be such a girl,” is still a playground taunt. Yet, at the same time, the hashtag created by online entrepreneur Sophia Amoruso, #girlboss, is a statement of empowerment – one which tacitly reminds us that actually the word “girl” doesn’t ordinarily go with “boss”. Real bosses are men.

It’s hard to know when the age of the girl began. There were early glimmerings in the birth of Girl Power, as the Spice Girls stormed the world in the 1990s, and the growth began of a kind of feminism-lite. Gradually, the girl invasion grew, so that now it seems that the way to make a splash with something is to get the word "girl" into the title.

Nowhere has that shift been more dramatic than in the world of publishing. Seminal “girl” book, The Girl With The Dragon Tattoo, was published in 2005. However, by 2009, according to American website The Book Insider, novels with girl in their title had yet to become a publishing phenomenon in the United States (there was only one that year). By 2011, there were 48, and, by last year, 79. In fiction, everyone seems to have been getting on the girl train. If this report were a novel, we would call it Gone Woman.

Last year, Canadian author Emily St John Mandel analysed books with “girl” in their title, and discovered that 65 per cent of the time, the “girl” was in fact a woman. Bestsellers that are actually about women include Gone Girl, Girl On A Train, Girl With the Dragon Tattoo, Girl In The Dark and The Good Girl.

Mostly, of course, this is a marketing fad, and one can’t help feeling that if many of the classics of previous eras were published now, they might be forced to give themselves a girl title. We might have had DH Lawrence’s Girls In Love, Wilkie Collins’s The Girl In White, and, even, Louisa M Alcott’s Big Girls, rather than Little Women. Instead of Daphne Du Maurier’s Rebecca, we might have had Drowned Girl. Jane Eyre could have been The Girl With The Plain Face. Even Wonder Woman would probably have had to be cut down in stature and maturity to Wonder Girl.

It’s a marketing trick that functions on two levels. Partly this is about putting up a sign so that readers know what they’re getting: a story about a woman who's probably either vulnerable, in peril or unreliable. Of course, some girl-titled books are doing what stories have done since the early folk and fairy tales and using the state of girlhood as a position of transition.

But others are pushing an empowerment message that has become rife, and is doing women much damage as it is good. Netflix’s series Girlboss, based on the life of American businesswoman Sophia Amoruso, is a case in point. The show’s title derives from #Girlboss, the book the entrepreneur wrote, it also is a reminder of the #Girlboss empowerment movement she created which inspired millions of Instagram posts on everything from clean eating to motivational quotes.

Shockingly, this empowerment movement is, for many, what counts as feminism today. Amoruso, in interview, has even balked at using the word "feminism", saying: “It feels very heavy. It doesn't feel positive for some reason … Maybe Girlboss is a new word for feminism.”

Is this a problem? Certainly it is. If Girlboss is the new word for feminism, then we have a crisis, and it’s one really we’ve known about for some time. As Ruth Whippman observed, last year, in an article for time.com: “Self-empowerment has steadily become the rallying cry of mainstream feminism, a kind of corporate-friendly, non-threatening feminism-lite. In its hyper-individualistic worldview, 'empowerment' does not mean a material gain in status or influence, but a feeling of inner potency. And in advising women how to maximize these feelings, the feminist movement has started to sound like a branch of the self-help industry.”

The “girl” empowerment movement is ubiquitous. It’s there in #Girlboss, in Nicole Lapin’s motivational book Boss Bitch, and even in Ivanka Trump’s Women Who Work (though Trump broke the trend and used the word “women”). Key to this “self-help” feminism is the idea that we do not blame men, or the system, or the patriarchy, we just get on, get empowered, and do our own boss thing.

There’s one way to fight back. We need to bring back an old-fashioned word, one that’s in danger of slipping from our vocabulary, and I don’t mean “feminism”. I mean “woman”.