Vocabulary What does 盟友 (めいゆう, meiyuu) mean? 盟友 (めいゆう, meiyuu) means sworn friend. Quick factsReadingめいゆうRomajimeiyuuPart of speechnoun 盟友めいゆうmeiyuusworn friend1noun sworn friendKanji in this word盟alliance, pact; oath友friend