Open Dictionary of English

The Open Dictionary of English (ODE, after the OED) is a multimedia learners' dictionary, published by 501(c)3 nonprofit organization LearnThat Foundation. It is fully integrated with LearnThatWord, the vocabulary and spelling tutoring program by LearnThat Foundation, and can also be used as a standalone dictionary.
The Open Dictionary of English cherishes English as a global language.
Its goal is to connect learners with words illustrating their usage and nuances in a lively multimedia format.
Genesis.
The ODE contains around 180,000 words. Word data is assorted from a range of online sources. The Open Dictionary of English is a collaborative project, based on Open Source materials, LearnThat's own resources, and partner APIs. It contains data from WordNet/Princeton University and Wiktionary, Google, Wordnik.com, Dictionary.com, Stands4.com, YouTube.com, OEDILF.com, Kylescholz.com, Best-Practice.com, and Forvo.com.
Features.
The Open Dictionary of English offers:
• Videos and video snippets showing word usage
• Images
• Pronunciations from around the world
• Interactive thesaurus
• Hundreds of usage examples for each word
• Idioms and limericks
• Definitions from multiple sources
• Translations in 37 languages
• Synonyms, antonyms
• Words that rhyme
• Origin and root word information
• Verb conjugations
• Tutoring comments and trivia
• Integrated LearnThatWord tutoring
Users can add, edit and flag resources, and a team of human editors reviews changes before including them in the resource.
The dictionary is currently in Public Beta.