kainic acidEnglishOxford New American Dictionarykainic acid /ˌkīnik ˈasid, ˌkaɪnɪk ˈæsɪd / ▸ noun Medicine an organic acid extracted from a red alga, used to kill intestinal worms. Chemical formula: C10H15NO4. – ORIGIN 1950s : kainic from Japanese kainin (from kainin-sō, name of the alga Digenea simplex from which it is extracted) + -ic.