Wordnik

Wordnik is the world's largest dictionary, with the mission of making every word of English available to everyone, everywhere.

Wordnik wants to give a 360-degree view of every word, and every word at Wordnik gets its own full page, with as much data shown as possible: a standard definition (if one already exists), example sentences; synonyms, antonyms, and other related words; space for community-added tags, lists, and comments; images from Flickr and tweets from Twitter; and statistics on usage, including how many times a word has been favorited, listed, tagged, commented-upon, and, of course, whether or not it's valid in Scrabble (and how many points it scores).

Wordnik also has an open API for web, bot, and native app developers.

Planetwork