「tsunami」は1896年にはもう英語だった。OEDに載る日本語は550超、最古は1577年

Many English speakers use the word "tsunami." It comes from Japanese. The big Oxford English Dictionary, or OED, says the first known use of the word in English is from 1896, in a newspaper in Iowa.

The OED has more than 550 words from Japanese. The oldest ones are from a book printed in 1577. Some new ones are "isekai" and "senpai." And "emoji" is not from "emotion." It means "picture" plus "letter" in Japanese.

English has been borrowing words from Japanese for more than 400 years. An article by OED editor Danica Salazar counts 552 Japanese loanwords in the Oxford English Dictionary. The two oldest, "bonze" (a Buddhist priest) and "Kuge" (court nobles), appeared in a travel book printed in London in 1577.

Some words have been in English longer than you might guess. The OED's earliest evidence for "tsunami" is from 1896, and "tycoon," from the Japanese "taikun," goes back to 1857. Others are recent.

"Emoji" is first recorded in 1997, and the dictionary says its likeness to "emoticon" is probably a coincidence. New words keep coming, too. In March 2024 the OED added 23 Japanese borrowings, including "isekai" and "kintsugi."

Dictionary dates can be misleading. The Oxford English Dictionary's earliest evidence for "tsunami" comes from an Iowa newspaper in 1896, yet the word did not get its own OED entry until 1986, ninety years later. "Karaoke," first recorded in 1977, entered the dictionary in 1993, and "kawaii," found in a New York Times headline in 1965, was added in 2010.

Being in the OED also says little about how often a word is used. The OED estimates that "emoji" appears about five times per million words of modern written English, but "kawaii" appears fewer than 0.01 times. Traffic between the two languages runs both ways. The OED calls some of these words boomerang words.

"Cutlet" went into Japanese as "katsuretsu," was shortened to "katsu," and then returned to English in "katsu curry," first seen in 1976. "Cosplay" made a similar trip from the English phrase "costume play." On the Japanese side, between 2003 and 2006, the National Institute for Japanese Language and Linguistics suggested plainer words for 176 loanwords used in public writing, such as "setsumei sekinin" for "akauntabiritii," the Japanese form of "accountability."