Synonyms that are in the dictionary are marked in green. Synonyms that are not in the dictionary are marked in red.
Antonyms that are in the dictionary are marked in green. Antonyms that are not in the dictionary are marked in red.
This reveals the Kindle's 'reading toolbar,' offering shortcuts for changing the font, viewing the table of contents, and more.
Source: https://screenrant.com/amazon-kindle-how-exit-book-get-home/