Dictionary / Vocabulary / お湯割り
おゆわり
alcohol diluted with hot water
Also written お湯割、御湯割、御湯割り
焼酎のお湯割りはいかが？
How about shochu mixed with hot water?
テキーラのお湯割りも美味しいらしい。
Tequila mixed with hot water is also delicious, it seems.