An example of a boycott is if a shop's owner mistreats a person because of their race. As a result, people stop going to the shop as a protest.
Another example of a boycott is if a factory is underpaying their employees so they can't make a living. As a result, all of the employees stop working there so that the factory is at risk of shutting down without workers.
Boycott: withdraw from commercial or social relations with (a country, organization, or person) as a punishment or protest.
I hope this helped!