It needs some more precise words, but is the only extension that works for this purpose in mozila

worked very well.

Great. It enables me write better now

Surprisingly compatible with Google Dictionary. Always room for improvement, e.g. more than 5 results at preview. Good.

Right-click a word to find synonyms and antonyms!

It is a very helpful add-on for quickly searching synonyms and antonyms. It is also light on resources. Highly recommended for those who compose texts on the browser for work or leisure.

Great extension!!