Added to the Vocabulary page, use Wordnik to look up a word, Wordnik’s aim is to give as much information as possible about any word. As well as definitions you can see example sentences including the word, a thesaurus entry which interestingly includes words used in the same context as well as synonyms. Each entry includes Flickr images tagged with that word. Wordnik does not require registration but does includes a social aspect, there are comments on each word. It is possible to sign up or alternatively login with Facebook.