Depending on how you count, it’s close to a million

http://www.slate.com/articles/life/the_good_word/2006/04/word_count.html

Global Language Monitor estimates * that—as of this writing—there are exactly 988,968 words in English. GLM has done a remarkable job suckering even the respectable press into believing that we're on the verge of adding the millionth word to English—at which point we'll presumably see another flurry of articles about GLM. Even so, its claim is a bogus one.