A dose is a measured amount of medicine or another substance meant to be taken at one time. When you're sick and take cough syrup, the label tells you the proper dose: maybe one teaspoon every four hours. Taking the right dose matters because too little won't help you feel better, while too much could make you sick in a different way.

Doctors carefully calculate doses based on a person's age, weight, and condition. A dose of medicine for an adult might be too strong for a child, which is why pediatricians prescribe smaller doses for younger patients. Pharmacists measure doses precisely, sometimes down to the milligram.

The word extends beyond medicine. You might say you need a dose of reality when someone needs to face facts, or describe getting a healthy dose of sunshine on a beautiful day. If your friend complains nonstop about losing a game, you might think they need a dose of their own medicine, meaning they should experience what they're putting others through.

People also use dose as a verb. A nurse doses patients with their medications according to a doctor's orders. The key idea remains the same: a specific, controlled amount of something, given for a particular purpose.