湯あか ゆあか scale (i.e. hard water coating in a kettle Meanings also 湯垢 noun scale (i.e. hard water coating in a kettle, etc.); fur Its kanji 湯 トウ · ゆ hot water, bath, hot spring In sentences Furigana ボイラは湯ゆあかがびっしりついた。 The boiler was heavily scaled. #76444