硬こう水すいこうすいFreq.FrequencyTop 100,000Meanings1nounhard waterWater with high mineral content, especially calcium and magnesium. Often contrasted with 軟水 (soft water).See also: 軟水この地ち域いきの水すい道どう水すいは硬こう水すいです。The tap water in this area is hard water.