I think that feature is new to many of us, this is the first time I have heard of this, thanks for sharing it.
According to this article, the feature was changes in spring of 2005 from Dictionary.com, but without much fanfare. Apparently a lot of people don't know, because Answers.com is hurting for traffic despite having some of the best advertising space in the world. I think the problem is the way the page is set up at Answers; you have to scroll down to find all the really obscure stuff, like technical dictionaries and the thesaurus. The site really is a miracle of convenience if you write on a lot of topics and need the correct info every time.