The word 'slut'

When I hear someone use the word 'slut' I know that the person in question is highly likely to be a decent sort of person, but that the speaker is someone with whom I should avoid innuendo or discussions of sexual issues.
It would be funny, I suppose, if it weren't such an effective tool for controlling women's actions.
It's not really a tool of the patriarchy or of misogynist men: it's used a lot more harshly by other women, who wish to control their fellow women, and use this as a means of social disapproval.
They do this because if some women sleep around a lot, or even a little, it makes the rest of the women, who don't, worth less to men. It's basic economics, and the use of the word slut is a negative advertising campaign to distort the free market.
Of course, these people tend to be social conservatives, and would never phrase it that way, because that tends to go with being economic conservatives, who worship the free market.