Word Discoverer highlights rare English dictionary words, idioms and proverbs on web pages.
It helps non-native English learners to discover new expressions while they are browsing the Internet.
Highlighting of rare words is useful because some people do not even notice vaguely known words, especially when these words are not critical for understanding of the text that they read. One possible explanation of this strange and pertexing effect is that mind of a reader is concentrated on understanding the meaning and structure of the text, and after finishing reading a sentence many readers won't go back to check the meaning of unfamiliar words that they have already forgot. E.g. some readers will forget to check the definition of word "pertexing" from the previous sentence which, in fact, doesn't exist. And even if you did check it, you still can try this extension, it highlights only real English dictionary words and idioms =)
Words Discoverer is free forever, open source, and it has no ads.
Words Discoverer is better than "Word-of-the-day" type of programs because new words are highlighted in context of the text that you read, which is a good motivating factor to finally check the definitions and learn these words (or idioms).
Depending on your vocabulary size, you can adjust frequency threshold of highlighted words e.g. skip 25% most common English words, and highlight all the rest. There's no way to set such threshold for idioms and proverbs, the extension can either highlight all of them or none.
Words Discoverer can operate in two modes:
Currently there are ~50K words and ~1600 idioms in the extension's dictionary. If you're interested you can look at them on project's github page.
Here some example of idioms from the dictionary: "brand new"(everyone knows this one), "bucket list", "moral high ground", "baby shower"(it is not a shower for babies), "money laundering", "jigsaw puzzle", "veil of ignorance". And there are many others.
If you known definition of a highlighted word, you can add it to your personal vocabulary and it won't be detected any more. When you add a new word it is converted to normal form for your vocabulary e.g. "dogs -> dog". You can always view your vocabulary or save it as a text file. To add a word - select it's text with mouse and right click to show browser context menu.
Words Discoverer provides basic dictionary lookup functionality: see the dictionary links in hovering window and in browser context menu. And, of course, you can also use Words Discoverer in combination with your favorite dictionary app (e.g. "Google dictionary" extension)
Words Discoverer respects your privacy, works locally in your browser, and doesn't send any of your data anywhere. It can even work offline if you have some html files saved on your computer.
Most adult native English speakers know 20000-35000 words, so it is totally possible to eventually add them all to your vocabulary file.
Backup your personal vocabulary to a text file periodically.
If you have dedicated dictionary extension installed in browser, you can disable online dictionary links that "Words Discoverer" provides. It will be easier to add new words after that.