Funny you mention it. The word elan actually is derived from the Middle French word “elance”, a verb meaning “to hurl”, specifically, lances and darts. As fads tend to do, lancing and dart-throwing eventually faded into the background and “elance” officially declined from colloquial English about a century and a half ago.
Just about that time, the word élan entered lexicon copying elements of the original medieval word, but with a bit more flair. Now in the 21st century, the word “élan” means with vigorous spirit or enthusiasm.