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Thesauri

Listings
Searchable WordNet and Roget's Thesaurus with meaning trees.
http://www.germ.cz/
Search for relationships between words and concepts that might never have occurred to you before.
http://www.lexfn.com/
A resource for writers. Enter a single word and it will return a list of phrases and sayings that are related to the word in some way. In English.
http://www.phrasefinder.co.uk/
Exploration of sense relationships within the English language.
http://www.visualthesaurus.com/
A creative phrase tool for creative writers of any genre including college students, people just learning English, people wanting to improve their communication skills, artistic professionals and others.
http://www.sybrina.com
Thesaurus of phrases and sayings in English.
http://www.phrases.org.uk/
Online version of the thesaurus of English words and phrases.
http://www.thesaurus.com/
Makes the words on any webpage into links so you can look them up in a dictionary or other reference site, by simply clicking on the words.
http://www.voycabulary.com/
American English dictionary with an integrated thesaurus and other lexical resources.
http://www.wordsmyth.net/