Wikimedia/Wiktionary
Wiktionary is a multilingual free online dictionary. Wiktionary runs on the same software as Wikipedia, and is essentially a sister project. It is currently owned by the Wikimedia Foundation. The project was started in 2002 following a proposal by Daniel Alston. It was originally located at wiktionary.wikipedia.org, but was later moved to its current domain (http://www.wiktionary.org/). It currently has over 3 million entries in English alone and in total more than 7 million content pages.