http://www.babylon.com/
http://www.idoceonline.com/
http://dictionary.cambridge.org/
http://dictionary.reference.com/
http://www.merriam-webster.com/
http://www.macmillandictionary.com
http://www.websters-online-dictionary.org/
http://www.yourdictionary.com/
http://www.synonym.com/
http://thesaurus.com/browse
http://www.alphadictionary.com
http://www.rhymezone.com/
http://www.rhymer.com/
http://www.thefreedictionary.com