a dirty untidy woman
"The old house was so messy that everyone joked about how much of a slut the previous owner must have been."
a woman adulterer
"After her husband found out she was having an affair, he called her a slut in front of their friends."
A sexually promiscuous woman or girl.
"The old-fashioned term was used to describe a woman who had many sexual partners before getting married."
In plain English: It is an old and unfair insult used to shame someone for being sexually active, but it has no real meaning other than hurtful judgment.
"The term is offensive and should not be used to describe people; instead, consider describing someone's actions without using derogatory language like that."
Usage: Avoid using this term to describe women who are simply dressed attractively, as it unfairly judges character based on appearance and behavior. It is often used derogatorily rather than descriptively when referring to a person with multiple sexual partners.
To wear slutty clothing or makeup, or otherwise behave in a slutty manner.
"She decided to get dressed up and slum it at the party by wearing a short skirt and heavy eye shadow."
In plain English: To slut is to engage in casual sexual activity with many different people without commitment.
"The rain began to slush down on our shoes until we were soaked through."
The word "slut" comes from Middle English terms meaning a dirty or slovenly person, often specifically referring to women. Its ultimate origin traces back through Old English to Proto-Germanic roots describing sleet and hail before evolving into its current sense of promiscuity.