To teach; to be a teacher in a school. Did you know that Karen teaches school? I thought she was stockbroker. Don't feel so bad. I've taught school for 30 years, and I still run into situations I don't know how to handle.

To convince one to avoid some unwanted behavior in the future through the inflicting of some form of punishment or harm. Can be said of the harm or punishment itself, or the agent inflicting the harm or punishment. After the CEO was found guilty, he was forced to repay $150 million in damages and will spend the next 10 years in jail. If that doesn't teach him a lesson, I don't know what will. A: "The cat scratched Bobby this time when he pulled its tail again." B: "Well, that ought to teach him a lesson." Are you going to mess with my little brother again, or am I going to have to teach you a lesson?