The One Correct Definition of a Word

I am wondering if the debates we have over certain words are often confused because we assume the word has one correct definition when it doesn’t. For example, does the word ‘atheist’ refer to someone who believes gods don’t exist or someone who just doesn’t actively believe in a god? Why would anyone think we have to define it one of these two ways, and that the other definition has to be wrong? Other examples include debates over the definition of ‘free will’ and ‘knowledge.’ The question is, “Is there really a correct way to define these terms?” We might think that debates over definitions isn’t really substantive because there is no essence corresponding to the words (at least some of the time). Words could also have a tendency to make use of family resemblance concepts that lack necessary and sufficient conditions, so it might be hopeless to try to define words based on how we actually use them using exact specifications. If there isn’t a single definition, then the debate could end up having various opposing views of how people should talk about things.