Let's not forget that words do not have intrinsic meaning. Words are socially constructed and don't hold or retain meaning in the literal sense. In the late 50s and early 60s the writers of dictionaries decided that the original model of meaning being a top down proposition was not correct. Before around 1960 the meanings of words were dictated by the ruling elite and academics in a top down manner. It was these people's definitions that would make it into the dictionaries.
But they realized that common usage should take precedent over an authoritarian model. So they began defining words as the masses understand and use them. This was a huge revolution in the subject of semantics, a subject I studied in college. What this means is, if say an influential person started declaring that the word "black" actually meant what we know as "white" and this use of the word black caught on to the point that say 80% of the world made the sound of "black" when referring to what we know as white, they would not be wrong. If comoon usage dictates that the majority of people refer to the light color as "black" then "black" would literally become the proper word for that light color, the color of a page etc. what we now know as white.
The implications go even further. under the current model of meaning, it makes no sense at all to tell a person that they are using a word wrongly. The reason for this is that as long as the person is successful in communicating a thought to another person, then the use of the word is correct, even if it is a completely new use of the word. The point is that the communication was a success and therefore all words were effective and "right" or correct. This is so even if the dictionary definition is the opposite of the way the person used the word. In years to come, unconventional usues for words become mainstream.
This is why it makes no sense at all to dig into ancient or some say "original" meanings of words. The fact is that we understand words the way we understand them, period. Words change meaning through time as concepts disappear and new concepts arise. One example is the word "gay." Gay originally meant happy or carefree. Now, the main definition of the word gay refers to a homosexual. The word for gay/happy is rarely used these days. Therefore a person is perfectly correct to assume that gay means homosexual. Original meanings of words are in stages of irrelevance at all times and sometimes they disappear altogether and become arcaic to the point of being untranslatable or unknown completely. Just try to read Shakespeare and you will experience this phenomenon.
What is important is that in the context of a conversation, each member of the conversation must know what the other person means when they use a certain word. You may speak with A and find out that he uses the word black to mean what you are accustomed to using as white. So during the conversation the two of you must agree, or literally "come to terms with one another, but just for that specific conversation. Then you go next door and speak with your neighbor, and he uses black to mean "tan." Now you must adjust you understanding to how he understands the word, or else convince him that just for the duration of the conversation he will use your definition of black. To say that he is "wrong would simply be out of line with the nature of meaning. Remember PEOPLE attach meaning to words. The words themselves are inanimate and have no capacity to retain or hold meaning. People just agree to use the word black to mean the dark color. if people change their minds, then black will literally mean whatever new definition that we all decide it should mean.