MONOLINGUAL DICTIONARIES

http://www.ats-group.net/dictionaries/dictionary-english-english.html

http://www.foreignword.com/Tools/dictsrch.asp?p=files/f_40_0.htm


http://www.merriam-webster.com/spell/index.htm



http://www.onlineordbog.dk/wordnet/en/03/monolingual.php