Dilution: the act of making a liquid or solution less concentrated by adding another liquid, or the resulting lower concentration. Commonly used for medicines, reagents, and test solutions.
この薬はそのままでは濃すぎるので希釈してから投与してください。
This medication is too concentrated as is, so please dilute it before administering.
検査用の試薬は指示された希釈倍率で希釈する必要がある。
The reagent for testing needs to be diluted at the prescribed dilution ratio.
ジュースが濃すぎたので水で希釈して飲んだ。
The juice was too strong, so I diluted it with water and drank it.