Kōjien Dictionary Day

What Is Kōjien Dictionary Day?

Every May 25th is "Kōjien Dictionary Day" (広辞苑記念日, Kōjien Kinenbi) in Japan. On May 25, 1955, Iwanami Shoten (岩波書店) published the first edition of the Kōjien (広辞苑) — a comprehensive Japanese-language dictionary that became the definitive reference for the Japanese language and a cultural institution without parallel in Japan's literary and educational life. The Kōjien's combination of encyclopedic breadth, linguistic precision, and the cultural authority of the Iwanami brand made it Japan's most trusted dictionary for generations.

The Kōjien and Japanese Language Authority

The Kōjien (literally "Garden of Wide Words") is a single-volume comprehensive dictionary that covers Japanese vocabulary from ancient literary language through modern usage, including proper nouns, scientific terminology, and encyclopedic information. Its entries not only define words but trace their origins and historical usage, making it simultaneously a dictionary, an encyclopedia, and a guide to Japanese cultural history. The authority of being "in the Kōjien" — of having a word recognized in Japan's most prestigious dictionary — has made new additions to each edition newsworthy events in Japan.

The Kōjien's Cultural Status

In Japan, the Kōjien occupies a cultural position somewhat analogous to the Oxford English Dictionary in the English-speaking world, or the Larousse in French — as the reference work whose authority is invoked to settle questions of correct Japanese usage. Each new edition (the seventh edition was published in January 2018) is a cultural event, with media attention focused on what new words have been added, what words have been removed, and what the changes reveal about evolving Japanese society and language.

Japanese Lexicography

Japan has a rich tradition of lexicography dating from ancient times, with major dictionaries compiled in the Heian period and Edo period. Modern Japanese lexicography — producing not only comprehensive dictionaries like the Kōjien but also specialized dictionaries for classical literature, foreign words, dialect, technical terminology, and every conceivable domain of language — reflects Japan's profound investment in linguistic precision and the preservation of its literary heritage.

Fun Facts

• A dictionary read backwards: In 1992, Iwanami published the "Gyakubiki Kōjien," a reverse dictionary that lets you look up words by their last character — handy for rhyming and word games.
• Its roots: The Kōjien grew out of "Jien," a dictionary compiled by linguist Izuru Shinmura and published by Hakubunkan in 1935. Work on its revision was interrupted by the war, and the revised dictionary finally appeared as the Kōjien about 20 years after the revision began.
• Digital Kōjien: While the printed Kōjien remains a prestigious physical object in many Japanese homes and offices, digital versions for computers, e-readers, and smartphones have made its reference function accessible to younger users who may never own the printed edition.