胃い酸さんいさんFreq.FrequencyTop 50,000Meanings1nounstomach acid; gastric acidMedical and everyday term for the acidic digestive fluid in the stomach.胃い酸さんが逆ぎゃく流りゅうして胸むねやけがする。Stomach acid flows back up and causes heartburn.胃い酸さんの分ぶん泌ぴつを抑おさえる薬くすりを飲のんでいる。I'm taking medicine to reduce stomach acid secretion.