这酒因掺水而味道不佳.The quality of the wine is diluted by water.那个酒吧招待在杜松子酒内掺水时被他们抓到了.They caught the bartender stretching the gin with water.他在酒中掺水.He watered down the wine....

“掺水”的英语可以翻译为：[经] watering ...