Word Hippo
![wordhippo](http://digitalliteracy.us/wp-content/uploads/2013/09/wordhippo-420x280_c.jpg)
Word Hippo is an online dictionary/thesaurus which offers a wide range of other tools including opposites, rhyming words, translation, and lots more besides.
There are probably other sites which offer the same or similar features, but I liked the simplicity of Word Hippo. The example sentences function is particularly useful for students and teachers who want to see how words are used in context.