If you’re a word lover, then you’ll go bonkers for the fun and learning you can have with Visual Thesaurus.  Just type in your word and you’ll be presented with an associative visual mapping.  In the example below, I keyed in “duplicitous” as my base word.  The various branches extend the meaning and history of the word with other words.  Hover over any of the words in the Visual Thesaurus interactive box and you’ll be presented with extended definitions.