object lesson

American  

noun

1. a practical or concrete illustration of a principle.

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object lesson British  

noun

1. a convincing demonstration of some principle or ideal

2. (esp formerly) a lesson in which a material object forms the basis of the teaching and is available to be inspected

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Etymology

Origin of object lesson

First recorded in 1825–35

Example Sentences

He and his representatives are now threatening Cuba, Mexico, Colombia, Iran and Greenland, with Venezuela serving as an object lesson of what may happen if a country dares to disobey his wishes.

From Salon • Jan. 6, 2026

Industry insiders have told the BBC that Fishwick is now regarded as an object lesson in how not to run an installation project.

From BBC • Oct. 30, 2025

As the kids grew older, she said, the business became a source of pride, and an object lesson in loyalty, endurance.

From Seattle Times • Feb. 16, 2024

Though he may be referring to setbacks in his gubernatorial career, such a position does not transfer easily across to Schwarzenegger’s personal conduct down the years, which has scarcely been an object lesson in integrity.

From Los Angeles Times • Oct. 6, 2023

He was a walking object lesson about how dangerous work in the Fishery could be.

From "The Name of the Wind" by Patrick Rothfuss