Thesaurus

In the Thesaurus, you get a huge variety of the synonyms of the words you look up. Also,  it provides you a short definition of the word you have looked up and in the part below it gives you word related to the one you have looked up.

Although it gives you a lot of synonyms and you may have problems to choose an adequate one, it gives you the chance to filter these synonyms according to relevance, complexity or length helping you with a colored rank.