津波

Japanese fishermen would sail out in the morning, fish all day in calm seas, and return to find their harbor destroyed—homes gone, families drowned. They never saw the wave at sea. It was invisible in deep water, rising only when it reached the shore.

So they named it for what they found, not what they saw: tsu (津)—harbor—plus nami (波)—wave. A harbor wave. A wave that exists only when it reaches you.

The word entered English after the great wave of 1896 killed 22,000 people in Japan. Western scientists adopted tsunami because English had no precise word—"tidal wave" was inaccurate.

Now the word has traveled back across every language, because the phenomenon knows no borders. When the Boxing Day tsunami hit the Indian Ocean in 2004, the Japanese word was on every tongue.