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.

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.

something to be learned or studied

the lessons of the past.

a useful piece of practical wisdom acquired by experience or study

That accident certainly taught him a lesson in careful driving.

something from which a person learns or should learn; an instructive example

Her faith should serve as a lesson to all of us.

a reproof or punishment intended to teach one better ways.

a portion of Scripture or other sacred writing read or appointed to be read at a divine service; lection; pericope.

to teach; instruct; give a lesson to.

to admonish or reprove.

noun

assignment , chalk talk , class , coaching , drill , education , exercise , homework , instruction , lecture , period , practice , quiz , reading , recitation , schooling , study , task , teaching , test , tutoringnotes:lessen means to decrease in size , extent , or range , while a lesson is a unit of instruction , admonition , censure , chiding , deterrent , exemplar , helpful word , message , model , moral , noble action , notice , precept , punishment , rebuke , reprimand , reproof , scolding , warningnotes:lessen means to decrease in size , warning , example , experience , text