noun, noun which may take the genitive case particle 'no'
diluted alcoholic drink; cut drink; watered-down drink
Typically refers to whisky or shōchū mixed with water. Can also refer to the act of diluting. Common in bars and izakaya.
ウイスキーの水割りをください。
I'll have a whisky and water, please.
水割りはアルコールが弱くなるので飲みやすい。
A diluted drink is easier to drink because the alcohol is weaker.