Meaningyounger sisterOn'yomiマイKun'yomiいもうとCommon compounds (6)妹 いもうとyounger sister姉妹 きょうだいsisters弟妹 ていまいyounger brother and sister義妹 いもうとsister-in-law (spouse's younger sister or younger brother's wife)実妹 じつまいbiological younger sister従姉妹 じゅうしまいcousin (female)