The word myriad has been popping up more and more lately. I even heard it in a show about the Great Barrier Reef, on sports newscasts and in business meetings. But, my understanding of the word that it should be used like the word “many.” However, whenever I hear it used it is used more like the work “lot,” as in “a lot.” Which is the proper usage?We love questions like this (even though they are more about usage than grammar). When questions like this pop up, though, it doesn't take SPOGG to answer them. A good dictionary--the Oxford English Dictionary is a favorite--will tell you all sorts of things about the origin of words. We log into the OED through our local library's site, which offers free subscriptions to patrons. Does your library? Check it out. That's what your tax dollars pay for.
We learned myriad has been used as a noun longer than it has been used as an adjective, even though many people prefer the latter use. Originally, it meant 10,000. Then it meant "a lot." As an adjective, it means "many."
Bryan Garner, author of the indispensable Garner's Modern American Usage, writes that "myriad is more concise as an adjective than as a noun...but the mere fact that the adjective is handier doesn't mean the latter is substandard." (Note: a brand new version of Garner's usage guide is out. We highly recommend it.)
In short: There's no need to spend any time wondering about what words mean and how they're best used. Make a habit of looking things up at the OED and in Garner's book, and you will fill your brain with useful language facts. SPOGG does love questions, of course. So keep on sending them!