Google Dictionary API

http://www.google.com/dictionary/json?callback=dict_api.callbacks.id100&q=plaudit&sl=en&tl=en&restrict=pr%2Cde&client=te
http://www.google.com/dictionary/json?callback=dict_api.callbacks.id100&q=test&sl=en&tl=en&restrict=pr
http://www.google.com/dictionary/json?callback=dict_api.callbacks.id100&q=test&sl=en&tl=en&restrict=de

q        = word 
sl       = source language
tl       = target language
restrict = is used to restrict the source of word definition
          valid entries include pr = primary, de = webDefinitions (word meanings from other sources)