It was a word commonly used by the KJV Bible, and therefore, was not a curse word to our general culture. However, some today act like it is. In reality, the word "whore" is seen as a not-so-nice word, so any godly person should simply not use it. Let me push back on that because I use it all of the time, and purposely so.
I don't use it to try and shame the women who have already repented of a lifestyle our wicked culture had convinced them was not as bad as it really is, but rather to show the severity of the crimes committed in the act of having sex with a man who is not your husband, before or after marriage.
The damage such an act does is overwhelming, and likely has far reaching implications that we have never even thought of before. When someone puts up a fence, only an idiot takes it down before he knows why it was put there. How much more are we the idiots for thinking we know better and taking down a fence God put up?
An example of a possible consequence we have never thought of is the ancient and sometimes modern idea that the children of your husband will never fully be his because you slept with another guy at some point in your life. Ever heard of telegony? It's considered pseudoscience by the mainstream and it may be, but there are a lot of questions surrounding how it exists in other species. Gene drift is certainly a thing, and it would make sense that if the two become one flesh, and the Bible talks about the child and the womb being spoiled when a woman lets another man in it, then there could be something beyond what we even know. I'm not a scientist and I don't frankly know (it could all be garbage science but our culture will never allow it to be anything but that because of their constant need to be an apologetic for the sexual revolution), but what I do know is that this is considered a horrible crime by God against the husband, far more horrible than our culture would ever want to admit or know about.
Either way, a harsher word is likely needed for a horrible crime, not a softer one.
But there is even more to my use of the word than that, and it is bound up in how translations often translate the Hebrew word זונה and the Greek word πόρνη, often translated as "prostitute." The words actually don't mean "prostitute" in the Bible, although contextually, they can refer to a prostitute. That's a big difference. What they mean divorced of any further referent in the context is far more stripped down than that. They simply refer to a woman who has sex with a man outside of being married to him. This can be a prostitute, but it can also just refer to a woman who does not take money for sex.
This is made clear in a few different passages. The first is Deuteronomy 22:13-21, where the girl is called a זונה for "not being a virgin." And, of course, the common discussion about whether בְּתוּלָה means "virgin" here is obvious as the test is checking whether she has bled or not.
Likewise, God charges Israel with being a זונה in Ezekiel 16, where He does reference the idea that a זונה in the sense of a "prostitute" always takes gifts in exchange for sex, but here, the adulterous wife is called a זונה even though she refused to take gifts, gave herself away for free, and even gave gifts to her lovers instead.
This is why some translate it as "played the harlot" or "acted like a prostitute," but this softens the blow a bit because it makes the woman "like" something, but not really that thing. Instead, God declares that she is that thing whether she took gifts for it or not.
It is also interesting that the sacrifice of children is brought up once again in this discussion in Ezekiel 16 because it seems to indicate that the act of זונה is an act that sacrifices a husband's children in some way, as Leviticus 18:20, which reads "You will not lie with the wife of your neighbor for offspring to be defiled in her."
It's interesting that the prohibition against sacrificing children follows this command in verse 21.
"Prostitute" connotes in our culture the idea that a woman is trading sex for money. That is why so many women don't think they are guilty of this horrible crime. However, if they knew that the Bible was talking about their sexual activity with any guy other than their future/present husband, and that it is labeled with a horrible word so that it is understood as a horrible crime, perhaps it would give at least some pause, and help future generations from casually committing this crime against the husband.
Ergo, I use the word "whore" because it is what we have become, a nation of whores and pimps that receive no money for these crimes, only the fleeting pleasure to be paid for by the pain and loss of the husband.