The phrase “one bad apple spoils the bunch” means that one person or thing can ruin the whole group or situation. It is based on the fact that a rotting apple can cause other apples near it to rot faster too. The phrase comes from an old proverb that says “a rotten apple quickly infects its neighbor” or “the rotten apple spoils his companion.” The phrase is often used to warn people to stay away from bad influences or to criticize someone who causes trouble for others. For example:
- I don’t want you hanging out with those kids. They’re nothing but trouble. One bad apple spoils the bunch, you know.
- We had to fire him because he was always lying and cheating. He was a bad apple who spoiled the whole bunch.
