You are assuming that it is a term that can be understood strictly from first principles. With an idiom, such an assumption is silly, as idioms come to their me

You are assuming that it is a term that can be understood strictly from first principles. With an idiom, such an assumption is silly, as idioms come to their meaning based on a series of historical events, accidental mis-uses, literary uses (and therefore references) and certain assumed shared views. So to understand why witch hunt actually makes sense as a term, you must first look at the real witch hunts that happened. These happened at a time and place where witchcraft was "known" to be real. Of course there weren't witches, but everyone then thought there were, so effectively hunting for witches was a valid thing to do. At the time, they also didn't know lots of other things, so if a person falls sick, or a cow dies, or a house burns down, scientific evidence based explanations were not so easy to come by. However witches were "known" to curse people, and a curse causes misfortune. So what would happen is a random person would decide to pay back a grudge, or look good to his fellow citizens or whatever, and accuse some 3rd party of witchcraft, for something like giving the evil eye, or dancing, or whatever. This would lead to a burning, and everyone would be happy again. Most of the time anyway. Sometimes, a series of unfortunate events would be construed as a major witch, or a whole coven of witches. Then everyone would go crazy, true beleivers would be terrified, ambitious social climbers would be accusing all their enemies of witchcraft, and so on. There would be attempts by authorities to get to the bottom of it, and many witches would be found. Mass burnings ensued, and eventually everyone would calm down and be happy again. So, looking back, this whole course of events is ridiculous, the root assumption of witchcraft is just plain silly. The mass panic/hysteria over it downright dangerous, and those taking advantage of the situation were repugnant. So, now, looking at the above situations, and refactoring a bit, so we can get a more generic algorithm, we see these key components: 1. A label that classifies someone as bad 2. A deep underlying fear of what the bad label stands for, but the fear must be non-specific. 3. A set of actions and vaguely sort-of correlated events (if you squint just right), that looks like: "bad things from #2 are happening to us!". 4. A set of people willing to manipulate the many for their own gain. If those conditions are met, you have a prime candidate for a "witch hunt" (keeping the name because it describes the original stuff well, and everyone knows what happened in those cases). Just start sending authorities after anyone labeled as the bad thing. There are of course some variations, and deeper nuances, but that is the gist of it.