Wiktionary

Wiktionary (whose name is a blend of the words wiki and dictionary) is a multilingual, web-based project to create a free content dictionary of all words in all languages. It is available in 172 languages and in Simple English. Like its sister project Wikipedia, Wiktionary is run by the Wikimedia Foundation, and is written collaboratively by volunteers, dubbed "Wiktionarians". Its wiki software, MediaWiki, allows almost anyone with access to the website to create and edit entries.