1. Something to be learned: lessons from observing nature.
a. A period of instruction; a class.
b. An assignment or exercise in which something is to be learned.
c. The act or an instance of instructing; teaching.
a. An experience, example, or observation that imparts new knowledge or understanding: The conversation was a lesson in tact.
b. The knowledge or wisdom so acquired. Missing the opening act taught me a lesson about being late.
4. often Lesson A reading from the Bible or other sacred text as part of a religious service.
tr.v. les·soned, les·son·ing, les·sons
1. To teach a lesson to; instruct.
2. To rebuke or reprimand.
[Middle English lessoun, from Old French leson, from Latin lēctiō, lēctiōn-, a reading, from lēctus, past participle of legere, to read; see leg- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.