Amazon for the Mac can create flashcards:
Amazon Device Support › Kindle for Mac › Read Books›
Read with Flashcards
Flashcards are note cards created for select content on Kindle for Mac, which include a word and definition. You can use them to test your memory of key terms and concepts.
• Access Flashcards: ◦ While reading, click on the Flashcards icon, located on the left side of the screen.
• Create Flashcards Decks: ◦ While reading click on the X-Ray or Notebook icon, and select the Export to Flashcards icon. Add a name for the Flashcards Deck and click OK to create a new entry.
◦ While reading click on the Flashcards icon and click on the plus icon at the top to create a new deck.
• Edit Flashcards: ◦ Click on Edit Deck at the lower right corner of the screen, select a section and make your changes, and then select Done. Click on Flip Sides to reverse the order of the information on your Flashcard.
◦ To delete a Flashcard, click on Edit Deck and then click on Delete Card and select OK.
• Use Flashcards ◦ While reading, click on the Flashcard icon and then select the set you want to use. Click on a card to read the other side.
◦ To shuffle your set, click on the Shuffle icon.
◦ To restart your set, click on the Refresh icon.
But how can I do something like that from Windows or Linux? Perhaps even typing in manually on the Kindle itself...