Words wax and wane. Words that were once in popular usage may descend into disuse as new words come along - their use increasing with each passing year. Then they too may become unfashionable and fade into obscurity. Furthermore, it seems indisputable to me that the use of words will often reflect fundamental aspects of human society at any particular time - just like our art, our architecture, our fashions or our music.
You can easily imagine that before the mid nineteen twenties, the word "television" was unheard of but then its use grew exponentially, reaching its zenith in 1996. It's the same with the word "laptop". Before 1980 it hardly existed at all but then its use began to storm upwards and that is still increasing.
How do I know these things? Well, I have been checking out a relatively new facility we can all access in Google. Type into Google the word "define" and then follow this with the word you wish to research. Click "Enter" and then, if your word is in the Google store, you will see it defined followed by a light grey arrow pointing downwards for more information about the word.
At the bottom you will see a usage graph and if you click on this you will get to the Google Ngram Viewer where you can see usage results in more detail. It's fascinating but it's mostly about published words - not the more difficult to quantify oral use of language.
I thought I would check out some more words, looking at declines and inclines. between 1800 and 2012. Here we go:-
"fantasy"
"goodness":-
"kindness":-
"Muslim":-
"obedience":-
"professional":-
"turmoil":-
And last but not least, "blogger":-
As I suggested before, we can read things into language use through the ages. The words we choose to employ speak of who we are. You could argue on this basis that there is more turmoil in the world today, more fantasy too but less kindness and goodness. Two words I didn't illustrate in this post were "love" and "family". It's nice to observe that the frequency of these words has remained pretty consistent through the last two hundred years. Why not check out some words that interest you? Do you think their use will be up or down?