Bryan Garner on "Plain English"
A word about "plain English." The phrase certainly shouldn't connote drab and dreary language. Actually, plain English is typically quite interesting to read. It's robust and direct—the opposite of gaudy, pretentious language. You achieve plain English when you use the simplest, most straightforward way of expressing an idea. You can still choose interesting words. But you'll avoid fancy ones that have everyday replacements meaning precisely the same thing.
Bryan Garner, from Legal Writing in Plain English, 2001, pp xiv