海草 かいそう Also written うみくさ, うみぐさ Meanings Noun marine plant; seagrass seaweed See also: 海藻 (かいそう). Kanji 海 sea. Read as カイ. 草 grass. Read as ソウ. Example sentences 海草を食べたのは初めてです。This is the first time I've had seaweed. あなたの国では海草を食べますか。Do you eat seaweed in your country? Jinuma: Japanese Dictionary · Word lists