Topsy-Turvy

Today at work, a co-worker was framing a photograph of a bunch of men on a boat which was heeled over on one side and looking as if it were about to topple, and so the word "capsize" popped into my head, followed immediately by the question, "Where could a word like 'capsize' come from, anyway?"

It doesn't sound or seem like any other word I can think of. It's obviously not a compound word. It doesn't feel like Dutch, my go-to language for nautical terms. I racked my brains for quite some time and couldn't make a go of it.

And with good reason! Nobody knows where it comes from. "Origin unknown", says Answers.com. "I concur", says the OED. (More or less: they have a couple of theories, one of them involving Spanish "cabo", "head", but that's just guesswork.) So: yet another one of those mysteries: a word that simply is.