Vocabulary What does 背 (せい, sei) mean? 背 (せい, sei) means height, stature. Quick factsReadingせいRomajiseiPart of speechnounLevel (estimated, JLPT framework)N5 背せいN5 · estimated, JLPT frameworkCommonseiheight, stature1noun height; statureExample sentences弟(おとうと)は背(せ)が高(たか)いです。My younger brother is tall.彼女(かのじょ)は背(せい)が低(ひく)いです。She is short.Kanji in this word背back; height; contrary