noun
kudzu starch gruel
A traditional Japanese hot drink made by dissolving kudzu (arrowroot) starch in hot water and sweetening it, often served in winter.
寒い日には、温かい葛湯を飲むと体が温まる。
On cold days, drinking hot kudzu starch gruel warms you up.
From 葛 (kudzu, arrowroot) and 湯 (hot water).