Reduce/Reduction: to make something smaller or use less, resulting in a smaller amount of waste.
"Source reduction" is reducing waste before you purchase it, or by purchasing products that are not wasteful in their packaging or use.
A key part of waste "reduction" is "conservation"—using natural resources wisely, and using less than usual in order avoid waste.
You can practice reduction by selecting products that do not have to be added to landfills or the waste stream in general. This is really easy to do...