She came up with the label more than two decades ago, envisioning a community where people who are unable to find sexual partners could turn for support.

She called it “involuntary celibacy”.

This week the movement that eventually grew out of that term burst into public view, after a man ploughed into a crowd of pedestrians in Toronto, killing 10 people and wounding 14 others.

Minutes before the attack, the suspect allegedly posted a short, cryptic message celebrating the “Incel Rebellion”, according to police in Canada.

The connection left the woman who invented the term reeling“It’s not a happy feeling,” said Alana, who asked that her last name not be published. “It feels like being the scientist who figured out nuclear fission and then discovers it’s being used as a weapon for war.”

A self-described late bloomer, she coined the term involuntary celibate in the late 1990s to describe her own experience of not having sex and not being in a relationship.

It soon snowballed into Alana’s Involuntary Celibacy Project, a simple, all-text website where she posted theories and articles as well as ran a mailing list. “I identified that there were a lot of people who were lonely and not really sure how to start dating,” she said. “They were kind of lacking those social skills and I had a lot of sympathy for that because I had been through the same situation.” The term was later shortened to “incel”.

The aim was to create an inclusive community, embracing those whose sex lives had been marginalised for reasons ranging from rigid gender norms to mental illness or social awkwardness.

Members of the site spanned all ages and sexual orientations, contrasting sharply with what the so-called movement would one day become. “There were some people who were kind of socially clueless, some people who needed a bit of education and some people who had the attitude that women are objects,” she said. “It was not virulent hatred, it was just ignorance and objectification. There was nothing like the hostility, hatred and misogyny that is happening now.”

Soon after her social life began to blossom and she handed off the site to someone she didn’t know. It would be years before she would hear the term incel again – this time as she was browsing through an issue of Mother Jones in a bookstore.

The magazine had covered the story of Elliot Rodger, who in 2014 killed six people and wounded 14 others in California. In online posts that raged at women for rejecting his romantic advances, Rodger had described himself as an incel.

“Holy shit,” Alana thought. “Look what I started.”

The term – and the friendly community of lonely people she had once fostered – had morphed into a deeply misogynistic online subculture that at times called for rape or other violence. Thousands were now on incel forums, united in their belief that the modern world is unfairly stacked against heterosexual men who are awkward or unattractive.

The term incel catapulted back into the headlines this week – this time closer to home for Alana. Toronto police said a Facebook page belonging to Alek Minassian, the accused in the Toronto van attack, appeared to connect him to incels.

Canadians authorities have yet to suggest any possible motivation for the attack, saying this week that questions as to whether the suspect had issues with women would be part of the investigation. While the victims were predominantly female, ranging in age from mid-20s to 80s, police said there was no indication that the suspect had deliberately targeted women in the attack.

Facebook confirmed that the post was made on an account belonging to Minassian and said his profile had been taken down after the attack. It remains to be confirmed whether the post is genuine and whether it was written by Minassian or someone who hacked into his account after the attack occurred.

The connection, however tenuous, prompted a bout of soul-searching. “I did entertain the thought that I might be kind of guilty for creating this monster,” Alana said. “But I don’t think I really am.”

In some ways the current community of incels parallels that which she once sought to create, with both made up of lonely people who are seeking some sort of mutual support to deal with the problem of not having sex. “The difference is the amount of hatred and the exclusivity and the attacking of women,” she said.

Looking back, she regretted not working harder to get academics and professionals to delve into the issue. But she was proud of the work she had done. “It’s frustrating,” she said. “I feel like I did something important, for the good of the world – that then turned out to be a weapon as well.”