When it comes to literacy, our society has been headed towards the lowest common denominator for a long time. The reason for this is a philosophical viewpoint on how the misuse of words should be handled. On both ends of this dispute, there are extremists.
One set of extremists thinks that how a word is currently used, regardless of how it may have been used a decade ago, should be what the word is understood to mean.
The other set of extremists seem to think that however a word was defined a century ago is how it should be understood.
In between, these two sets of people are those who acknowledge that words evolve and their meaning changes but that there should be linkages to what the word formerly meant.
At the beginning of the twentieth century, Dictionaries were viewed as a standard of definition. But now, most dictionaries are intended by the publishers to be a travel guide to the wild hinterlands of the way the natives speak their language. That last sentence is only slightly exaggerated.
The problem is that communication requires some degree of linkage to the past. For example, when a contract or a will is drawn up, the meaning of the words used in that document are supposed to be understood to mean what they meant at the time the document was written.
If the meaning of the document becomes an issue 30 years later and there is no "standard" for defining the word meanings then the whole concept of contracts and wills becomes an absurdity.
Let me provide an example of a couple of words that have changed meanings.
If you pick up a book from the time of Arthur Conan Doyle (such as the Dr. Thorndyke books) and the author uses the word "transpire," the author probably does not mean by that word what most people consider that word to mean today.
Back then, the word transpire meant "as the facts began to come to light." When a news story first breaks, the reporters may only know that someone has been shot. They may not know who shot the victim, they may not know the provocation or the motivation, they may not know the victim's identity, they may not know whether the victim's wound is critical or minor. As more information is learned, the facts transpire.
But today, people often use this word to mean "as subsequent events occurred" not as the facts became well known.
Another example is the word "awesome." There is a scene near the end of the movie "Quigley Down Under" that illustrates the earlier meaning of the word "awesome." A troop of British army soldiers arrive to arrest Quigley and he appears to be in a hopeless situation. Suddenly, Native Australians appear on the crest of the ridge surrounding the location of this encounter. The soldiers consider this an awesome sight and withdraw.
Today, awesome has come to be synonymous with "wonderful".
I find when teaching Bible classes that many younger adults misunderstand what the Bible means when it says that God is awesome. It doesn't mean that He is wonderful, it means that He is fearsome. See for example, Jeremiah 20:11 where the NKJV uses the word "awesome" but many other translations use words that are still able to be understood
The editor of Black's Law Dictionary decided a number of years ago that a book which discussed words that were in the process of changing or which had already reached a point that their meaning of a century ago was no longer the meaning that most people of all levels of literacy intended in their usage was needed. The fourth edition of that book was published in 2016. Although an ebook came out soon afterwards, an app for mobile devices was made which is much more useful than the ebook,
Here is a link to Google Books's listing of this book: