Flashcard (noun)

A card with a word, picture, or other information on one side, used as an aid in memorization or study.

Origin:

Mid 19th century: from flash (verb) in the sense "display suddenly" + card.

Examples:

1. She used flashcards to study for her vocabulary test.
2. He used flashcards to memorize the capital cities.
3. She used flashcards to learn a new language.
4. He used flashcards to study for his history exam.
5. She used flashcards to memorize math formulas.