noun
vinegar diluted with water; vinegar-water mixture
Refers to a mixture of vinegar and water, often used in cooking or cleaning. The term is straightforward and has no special register or rarity.
野菜を洗うときは、酢水を使うと良い。
When washing vegetables, it's good to use vinegar diluted with water.
このレシピでは、酢水に漬けてから調理する。
In this recipe, you soak it in vinegar-water before cooking.