Your answer made me wonder so I looked it up:
What is the difference between a tsunami and a tidal wave?
Although both are sea waves, a tsunami and a tidal wave are two different and unrelated phenomena. A tidal wave is a shallow water wave caused by the gravitational interactions between the Sun, Moon, and Earth ("tidal wave" was used in earlier times to describe what we now call a tsunami.) A tsunami is an ocean wave triggered by large earthquakes that occur near or under the ocean, volcanic eruptions, submarine landslides, or by onshore landslides in which large volumes of debris fall into the water.

Yes. Though that was always a bad idea, because they had nothing to do with the tides, or with true tidal waves. We borrow from Japan, because there was no word in English, just like we borrowed nearly every other word in the compost heap called the English Language.

(Did you know that we had to borrow, "pork" and "beef" from the French, in case someone tried to serve the pigs and cows up alive. Just think how tricky that would be in a posh eating house ! )

@Fernapple LOL I never knew that. As a vegetarian I can't even eat them cooked, let alone alive. Good grief!