I picked up a copy of Dictionary of Obsolete English that was on sale at one of our local libraries. The book was written by Richard Chenevix Trench, DD, Archbishop of Dublin, and published by the Philosophical Library, New York, in 1958. I bought it with the idea that inside would be some uncommon words that I could use in my writing, but a quick glance through it quickly rid me of that idea. I read the Preface to see what was actually going on and the Archbishop wrote that he hoped to provide a list of words that no longer mean what they used to mean. To put it in his language, he wrote: "Sometimes the past use of a word has been noted and compared with the present, as usefully exercising the mind in the tracing of minute differences and fine distinctions; or again, as helpful to the understanding of our earlier authors, and likely to deliver the readers of them from misapprehensions into which they might very easily fall; or, once more, as opening out a curious chapter in the history of manners, or as involving some interesting piece of history, or some singular superstition, or, again, as witnessing for the good or the evil which have been unconsciously at work in the minds and hearts of those who insensibly have modified in part or changed altogether the meaning of some word; or, lastly and more generally, as illustrating well under one aspect or another those permanent laws which are everywhere affecting and modifying human speech."
And, he lists alphabetically some of the words that have changed meanings from what they used to be or represented, like "harlot" which was originally used of both sexes for the most part as a "slight or contempt", and now as interchangeable with "whore" and for the female sex generally, as an example.
I'm sure that if I study them long enough, I may be able to adapt some of the words to cowboy novels and may have already done so like with the word "explode" which used to mean "to drive off the stage with loud clappings of the hands" and now could mean about anything that makes a loud noise when set off or shot.
I will continue to "peruse" (not listed in the book) the list of words for possible use in my writings and along with Thirty Days to a More Powerful Vocabulary possibly come up with a better written product.