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surname; family name
hereditary title (used in ancient Japan to denote rank and political standing)
「姓」 has another reading with different meanings.
日本で一番多い姓は何ですか。
What is the most common surname in Japan?
彼女は結婚して姓が変わった。
Her surname changed after marriage.
彼の姓はとても珍しいものだ。
His surname is very unusual.