Words with Unexpected Meanings based on the Kanji they are made of

[polv]

For the true? origin of 交番, see

On the origin of 「交番」

I just came to 「交番」（こうばん） in my lessons, and the mnemonics said: I have no idea how this one works, admittedly. You mix a number in a series and you get a police box. A police box? I remember watching a variety TV program once in Japan where they asked this of the guests, and they were all stumped. At the time, all I could gather from the explanation was that the current name was short for something else that I couldn’t understand. But it turns out it comes from the combination of 「交替」（こうた…