Word Webs

According to their website, it is "Brainstorming made fun."  Just like making up a mindmap but it lists related or associated words to the one you submit.  Attached to each word or node will be 6 associated words.  You can branch off from any of these words.  To see the website click here.

Word Hippo

Word Hippo is a website that according to them is "a Thesaurus and word tools for your creative needs."    You can search a word and look based on  synonyms, antonyms, definitions, rhymes, sentences, translations and more.  To see the website click here. 

Visual Thesaurus

This site displays word maps that blossom out with related words.  For example I used the word "slow" and here is what i received from my query.

This is a not a free site but you can try a few words or get a 14 day risk free trial.  To see the website click here.