Sometimes words are used by their textbook definition, other times they are used to misrepresent something, and sometimes they are used to signal. When one person says to another that something is one of these words, the other person probably won’t investigate it; he knows he shouldn’t touch it. It’s poisoned. It’s toxic. It’s bad. It’s evil. He might even get concerned enough to spread the word and let other people know how bad something he just heard about is. Associating with witches will make you guilty of being one, so why not save other people the misfortune?