In every round, the group gets the same secret word except one player. That player is the Imposter. Everyone takes turns giving a short clue that fits the word without saying it directly. After a few clues, you discuss who sounds fake, then vote. If you vote out the Imposter, the group wins. If the Imposter survives, they win and depending on the mode, they may also get a chance to guess the secret word.
Tip: Clues should be specific enough to prove you know the word, but not so obvious that the Imposter can guess it.