やかいそう 夜開草 LinksSentence search for 夜開草Sentence search for やかいそうSentence search for ヤカイソウKanji details for 夜, 開 and 草Edit in JMdict Noun1. moonflower (Ipomoea alba)Usually written using kana alone, Rare term, See also 夜顔Other formsヤカイソウ Discussions Log in to talk about this word.