The Sanseid? kokugo jiten (?, Sanseido's Japanese Dictionary), or the Sankoku () for short, is a general-purpose Japanese dictionary. It is closely affiliated with another contemporary dictionary published by Sanseido, the Shin Meikai kokugo jiten.
The Sanseid? kokugo jiten has been revised about once a decade.
Japanese linguist and lexicographer Kenb? Hidetoshi (?, 1914-1992) was chief editor of the first four editions. Among his prominent coeditors, Kindaichi Ky?suke (, 1882-1971), his son Kindaichi Haruhiko (, 1913-2004), and Yamada Tadao (?, 1916-1996) began with the 1st edition; Shibata Takeshi () with the 2nd; Hida Yoshifumi (?) with the 4th; and Ichikawa Takashi () began editing with the 5th edition Sanseid? kokugo jiten. Several of these lexicographers worked together on a predecessor Sanseido dictionary, the Meikai kokugo jiten (). Kenb? began working with its chief editor Kindaichi Ky?suke on the 1st edition (1943) and was an editor on the 2nd edition (1952).
In 1959, Sanseido placed Kenb? in charge of the Sanseid? kokugo jiten, and subsequently put Yamada in charge of the comparatively larger Shin Meikai kokugo jiten (1972 ... 2005). The 1st edition Sanseid? kokugo jiten (1960) had 57,000 headwords, while the 2nd-5th editions increased the numbers to 62,000 (1974), 65,000 (1982), 73,000 (1992), and 76,000 (2001) respectively.
Emphasizing contemporary usage is one of Sanseid? kokugo jiten's most significant contributions to modern Japanese lexicography. Many traditional Japanese dictionaries copy usage examples from earlier dictionaries, often taken from Classical Japanese language sources. When Kenb? Hidetoshi began compiling the 1st edition, he started collecting Japanese word usages from newspapers, magazines, and broadcasts, which he would write on cards. By the time he died, he had recorded some 1,400,000 usage example cards.
Like the other Sanseidou dictionaries, this one has a strong contemporary emphasis and shows the influence of its late editor's renowned citation collecting. The entries include many colloquialisms that were missed or ignored by other lexicographers. (1999)