tsuwm,
Thanks for providing the link to a plausible word count of the English language. There I read:
"The number of words in English has grown from 50,000 to 60,000 words in Old English to about a million today. "
(from your first link)
The first article I read in which it was stated that English included about 600,000 words. That was about 1975 because I was in graduate school then and that's when I would have read the article.
Several years later--maybe ten or so--I read another article that stated the language had grown to 800,000 words.
And there's your link stating the language has grown to a million words.
I've always wondered whether a word taking on a new definition increases the count by one. I would expect so. That's why I become a little excited when I learn a new meaning of a familiar word. I figure I've increased my vocabulary by one.
Now back the first article I read in about 1975. It was in that article that I read that French (I do believe, but could easily be incorrect) was in second place. [That's counting forward by one, Faldage, for the record.] And English, at that time, had over twice as many words as that language in second place.
But I'll begin my googling, and the verb to google really should be a word included in the dictionaries if duologue, a by far less-used word, is included.
