These days the word is often used as an affectionate tease among friends, especially adolescent girls. Or it has metaphorical meaning – you’re a slut for something you can’t resist.

At first it might seem that feminism and the sexual revolution have dulled the word’s power to demean: how can anyone be a slut – “a promiscuous woman,” as The Canadian Oxford Dictionary puts it – if females are free to be as sexual as men?

The word has become so benign that there’s at least one “Slut” line of clothing, not to mention lip balm and bubble bath bearing the word.

You could argue that the “slutification” of female fashion has further demolished the barrier between what used to be considered “good” and “bad” girls.

But “slut” can still pack a knockout punch of contempt, even when it’s aimed at someone who isn’t being, well, slutty. For people lashing out against a girl or woman, the four-letter word is – like “bitch” – one of those reflex insults that leap from the tongue.

Why does it pop up so readily? Because it can still hurt.

Witness Barbara Amiel Black’s meltdown last week in a Chicago courthouse, in which she called a female Canadian TV producer a “slut.” Apparently, Black was upset by the journalist’s assertiveness in trying to get into the same elevator – not exactly sluttiness in the traditional sense.

The word first emerged in Middle English as “slutte,” which denoted a dirty, untidy woman, a meaning it still bears in the U.K. By the middle of the 15th century, it had acquired its taint of sexual licentiousness.

Until recently in North America, that was the only sense in which it was used. (In fact, “slut” is one of the few judgmental terms from pre-sexual revolution days that still has currency. “Loose,” “floozy,” “easy” and “has a reputation” now seem awfully quaint.)

The funniest bit of pop culture to remove some of the sting from “slut” was the Saturday Night Live “Weekend Update” skit in which Dan Aykroyd routinely addressed co-anchor Jane Curtin as “Jane, you ignorant slut.”

Marcel Danesi, an anthropologist at the University of Toronto who teaches semiotics and youth culture, observes that “slut” is now an ambiguous word whose various meanings include – in hip-hop – “my woman.” Yet he was taken aback when a colleague called him a “slut” recently. “I was complaining about the inane bureaucracy at the University of Toronto, and he said, `You’re a typical slut …’ It was kind of friendly – he was saying that I break the rules.”

To him, “slut” still reverberates with negative connotations linked to sexual promiscuity. “I would never, absolutely never, present my wife in this way.”

Among younger people, though, the friendly use of “slut” is common. Mimi Hagiepetros, a 13-year-old Toronto student, says her schoolmates mostly use it “lovingly” and “as a joke.”

Grown-up women will good-naturedly call each other “slut,” employing the word with all its sexual connotations in subtle, ironic rebellion against a double standard that refuses to go away.

Yet the word hasn’t been completely defanged. A battery-operated Little Mermaid Shimmering Lights Ariel doll that supposedly says the words “You’re a slut” made it to the ABC news website last December after a “shocked” mother contacted the media. Visitors can watch a 48-second video clip of the doll “speaking” to try to hear the offending words themselves (Mattel denied the accusation, and this writer was unable to detect any Exorcist-like language).

Another cartoon creature, Paris Hilton, vigorously defended herself in a July interview with the celebrity gossip website TMZ.com against readers’ assertions that she was a “stupid, ugly slut” and “an overused human condom.”

“I am not a slut at all,” she declared. “I’ve only had a few boyfriends, and I don’t even do anything with them any more … I’m far less promiscuous than any of my friends.”

The best defence against being relegated to slut-dom, it seems, is to point a finger at women who are sluttier.

Amiel herself stoked controversy in a 2003 column for London’s Telegraph in which she discussed the word provocatively. “A woman can look and behave like a slut – it’s her right – and there will be no consequences,” Amiel wrote. “She may consent to intercourse on Thursday night, but if the chap is discourteous on Friday morning, the previous evening’s sizzling sex will cool into rape.”

Whatever one makes of Amiel’s argument, it’s clear that, for all our jocularity about the “s” word, it can still shock.

Toronto filmmaker Andrea Dorfman completed a documentary called Slut a year ago in which 10 females talk about having been labelled the slut of their class. “Literally, the 15-year-old had the same story as the 85-year-old,” says Dorfman. The film’s older subjects, “carried (the insult) around with them their whole lives. It affected their self-confidence, their careers, their self-esteem.”

Dorfman, 38, says a girl who’s branded a “slut” in gossip – and she adds it’s usually females who use the word against other females, competing for the attention of the still-more-powerful male – “is the receptacle of everybody’s anxiety about sex.”