“On the evening of June 15, 1896, the northeast coast of Hondo, the main island of Japan, was struck by a great earthquake wave (tsunami), which was more destructive of life and property than any earthquake convulsion of this century in that empire.”
This was perhaps the first time the word “tsunami” was introduced to English users – in an article in the September 1896 issue of National Geographic magazine, given in parentheses and in italics as the Japanese word for “great earthquake wave”.
“Tsunami” is, in fact, composed of the Japanese tsu meaning “port, harbour”, and nami meaning “wave”, and pronounced with the initial “ts” as in the Japanese.
In spite of its appearance in National Geographic, the word did not, in fact, gain much traction in the English-speaking world in the 19th century, though its use is noted in geological articles in the early 20th century.