Dilution means making something weaker or less concentrated by mixing it with something else, usually water or another liquid. When you add water to orange juice concentrate, you're diluting it to make it drinkable. When a cook dilutes a sauce that's too salty, they add more liquid to reduce the saltiness.

Scientists use dilution carefully in laboratories. A chemist might dilute a strong acid by slowly adding it to water (never the other way around!) to make it safer to work with. Doctors dilute certain medicines before giving them to patients to ensure the dosage is exactly right.

The word also describes weakening something non-physical. When too many similar stores open in the same area, they dilute each other's business: each store gets fewer customers because they're all competing for the same people. When a company issues more shares of stock, it dilutes the value of existing shares. When you add too many ingredients to a recipe that worked perfectly, you might dilute the original flavors you loved.

In all these cases, dilution means spreading something across more space or volume, which reduces its strength, intensity, or concentration in any one place.