50 cards: the word on the front, the definition on the back. Look at the word, say the definition to yourself, then turn the card over and be honest about whether you had it.
Every card starts unknown. Cards you miss come back within a few cards, and the gaps stretch as you learn them, until every card is learned.
For cards you already know: one pass through the deck. A miss drops that card back into the learning schedule.
Read through the cards with both sides showing.
Keys: any key shows the definition, then ← missed, → got it. On a phone, tap the card, then swipe left or right.