Vocabulary What does 有用 (ゆうよう, yuuyou) mean? 有用 (ゆうよう, yuuyou) means useful; helpful. Quick factsReadingゆうようRomajiyuuyouPart of speechna-adjective, noun 有用ゆうようyuuyouuseful; helpful1na-adjective · noun useful; helpfulKanji in this word有have, possess用use