Here are some examples:
* Reduce the amount of sugar in the recipe.
* Reduce the speed of the car.
* Reduce the size of the file.
* Reduce the noise level.
* Reduce the price of the product.
It can also mean to bring down to a simpler form or to make something easier to understand.
For example:
* Reduce the complex equation to a simpler one.
* Reduce the lengthy report to a summary.
"Reduce" can be used as a verb, noun, or adjective depending on the context.