(せい)

せい
noun
surname; family name
1. surname; family name; last name
A person's family name, as opposed to their given name. In Japanese naming order, the surname comes first.
(せい)(めい)()いてください。
Please write your surname and given name.
結婚(けっこん)して(せい)()わった。
My surname changed when I got married.
日本(にほん)では夫婦(ふうふ)(おな)(せい)名乗(なの)ることが法律(ほうりつ)()められている。
In Japan, the law requires married couples to share the same surname.

USAGE:
(せい) is a formal word for surname. In everyday speech, 名字(みょうじ) or 苗字(みょうじ) is more common. (せい) appears frequently on official forms and in formal writing.

COMMON COLLOCATIONS:

  • (せい)(めい) (surname and given name)
  • (せい)名乗(なの)る (to go by a surname)
  • 旧姓(きゅうせい) (maiden name; former surname)
  • 夫婦(ふうふ)別姓(べっせい) (separate surnames for married couples)

SIMILAR WORDS:
名字(みょうじ) is the everyday equivalent. () is used in formal/legal contexts. (せい) falls in between.