The devastating destruction and loss of life caused by waves triggered by a massive earthquake off the coast of Sumatra, Indonesia, in December 2004 catapulted the word tsunami into the global consciousness. Until this tragic event, most Japanese people were unaware that the Japanese word for such waves had also been adopted in English. The first recorded usage of tsunami in English was in April 1946, when a huge earthquake in the Aleutian Islands triggered a wave that struck Hawaii, and the local newspaper there decided to use the word that Japanese-American residents were using. The word spread rapidly, and in 1968 a proposal by the American oceanographer Van Dorn to make it an official academic term was accepted.

In July 2002, a Washington Post report on financial scandals involving Enron and other firms carried the headline "America Hit by a Tsunami of Scandal." Tsunami has now become such an established word that it is even used in a metaphorical sense. The word was used extensively by CNN and other media outlets after the recent disaster in the Indian Ocean and even appeared on the front cover of Time.

The word tsunami was first coined in Japanese in the Edo period (1603-1868). Combining a character meaning port (tsu) and the character for wave (nami), the word conveys the idea of a wave striking a port. Although it now refers only to big waves caused by earthquakes, it was originally also used for waves caused by typhoons and other storms.

At the meeting of world leaders held in January to coordinate relief efforts (the "Tsunami Summit"), Prime Minister Junichiro Koizumi was surprised to be asked by Prime Minister Lee Hsien Loong of Singapore whether the Japanese story Inamura no hi, which tells of people being saved from a tsunami by burning rice straw, was true. This story is set in what is now Wakayama Prefecture in 1854. In it, shortly after a big earthquake a man instinctively realizes that a tsunami is going to strike and sets light to bales of rice straw - his crop for the season - to guide the villagers away from the danger. Based on a true story, this episode was introduced to non-Japanese readers by the author Lafcadio Hearn.