Visuwords is a combination dictionary and thesaurus that gives you a visual “cluster” of meanings and synonyms for a word. It’s similar to the well-known Visual Thesaurus, but one major difference is that Visuwords is free.
It doesn’t provide the words in the context of a sentence, but it can nevertheless be a helpful tool to English Language Learners. Plus, it looks cool!
I’ve placed the link in both the Dictionaries and Thesaurus categories on the English Themes For Beginners and Early Intermediate page of my website.
I should point out that I recently read a critique from a teacher saying that some synonyms Visuwords came up with were inappropriate for students. I’ve tried it quite a bit, as have my students, and haven’t experienced that problem at all. But you might just want to be aware of that concern.