Pronunciation: (les'un),[key] —n. 1. a section into which a course of study is divided, esp. a single, continuous session of formal instruction in a subject: The manual was broken down into 50 lessons. 2. a part of a book, an exercise, etc., that is assigned to a student for study: The lesson for today is on page 22. He worked assiduously at his music lesson. 3. something to be learned or studied: the lessons of the past. 4. a useful piece of practical wisdom acquired by experience or study: That accident certainly taught him a lesson in careful driving. 5. something from which a person learns or should learn; an instructive example: Her faith should serve as a lesson to all of us. 6. a reproof or punishment intended to teach one better ways.
7. a portion of Scripture or other sacred writing read or appointed to be read at a divine service; lection; pericope.
—v.t. 1. to teach; instruct; give a lesson to.
2. to admonish or reprove.