is a single-volume Japanese dictionary first published by Iwanami Shoten in 1955. It is widely regarded as the most authoritative dictionary of Japanese, and newspaper editorials frequently cite its definitions. As of 2007, it had sold 11 million copies. Izuru Shinmura Kōjien was the magnum opus of Shinmura Izuru, 1876–1967, a professor of linguistics and Japanese at Kyoto University. He was born in Yamaguchi Prefecture and graduated from the prestigious Tokyo University, where he was a student of . After studying in Germany, Ueda taught comparative linguistics and edited foreign-language dictionaries in the latter part of the Meiji era. Through his tutelage, Shinmura became involved in Japanese language lexicography. Even Kōjien editions published after his death credit Shinmura as the chief editor. History Jien The predecessor of Kōjien originated during the Great Depression in East Asia. In 1930, the publisher Shigeo Oka (岡茂雄, Oka Shigeo, 1894–1989) wanted to create a Japanese dictionary for high school students. He asked his friend Shinmura to be chief editor, and they chose the title Jien (辞苑 "Garden of words") in a classical allusion to the Ziyuan (字苑, "Garden of characters") Chinese dictionary. Shinmura appointed his son Takeshi Shinmura (新村猛, Shinmura Takeshi, 1905–1992) as an editor, and in 1935, Hakubunkan (博文館) published the Jien dictionary. It contained some 160,000 headword entries of old and new Japanese vocabulary, as well as encyclopedic content, and quickly became a bestseller. 1st edition The editors began working on a revised edition, but the 1945 Firebombing of Tokyo destroyed their work. After the war, Shinmura and his lexicographers began anew in September 1948. Iwanami Shoten published the first Kōjien in 1955. It included approximately 200,000 headwords, about 40,000 more than the Jien. 2nd edition The 2nd edition (1969) deleted about 20,000 old entries and added about 20,000 new ones, especially scientific terms. On December 1, 1976, a revised and expanded version () of the 2nd edition was published. 3rd edition The 3rd edition (1983) added 12,000 entries, and was published in CD-ROM format in 1987. 4th edition Three major Japanese publishers released new dictionaries specifically designed to compete with the Iwanami's popular and profitable Kōjien: Sanseidō's Daijirin (大辞林 "Great forest of words", 1988), Shōgakukan's Daijisen (大辞泉 "Great fountainhead of words", 1995), and Kōdansha's Nihongo Daijiten (日本語大辞典 "Great dictionary of Japanese" 1989). In response, the 4th edition Kōjien (1991) was a major revision that added some 15,000 entry words, bringing the