To try the thousands of add-ons available here, download Mozilla Firefox, a fast, free way to surf the Web!
CloseWelcome to Firefox Add-ons.
Choose from thousands of extra features and styles to make Firefox your own.
CloseReview for Synonyms dictionary EN-US by cookie
Rated 4 out of 5 stars
I haven't been using it for long but it works. Maybe you need to have libreoffice installed, which I do. Windows 8.1
To create your own collections, you must have a Mozilla Add-ons account.