There's The Rub

It happened again yesterday. (It happens, as you can imagine, pretty often.) I used a word, and then I stopped to wonder exactly how it came to mean what it means. Luckily, I was at home, so the conversation wasn't irreparably damaged.

"Diatribe" is a strange-looking word, isn't it? Its first half is Greek "dia-", which usually means "through/thorough" in some way, and the other half...is a word all by itself. It doesn't make any sense.

But that's English for you. "Tribe", from Latin "tribus" (possibly related to "tri-", "three"), is unrelated to "diatribe", which is Greek through and through, stemming from "tribein", "to rub". How odd!

A diatribe was originally a lecture, of the educational sort, from the verb "diatribein", "to wear away"; the diatribe was a closely reasoned argument which had worn away many hours of study and writing (and would probably wear away a few more in the telling, and quite possibly wear away at the patience of the audience). Eventually, in English, it came to mean another sort of lecture, which is to say a harangue.

"Tribein" also gave English "tribulation", for obvious reasons, and "tribadism", which is an old and rather hilarious word meaning "lesbianism", because people figured that without any penises in sight, all a couple of ladies could manage to do was rub up against one another. I reckon the ladies in question figured out some other ways to enjoy themselves.