Now there's a dandy word I haven't heard for a while. I had no luck trying to find etymology. Share and share alike.
Remember using logarithms, and having to find reciprocals?
I had no luck trying to find etymology.
That's because its is a troubled one. From Latin reciproco 'to move backwards, or back and forth'. The re- prefix is familar, but the rest of the word is murky. Cf. Latin procer 'chief, noble'. But where did the -ci- come from? Some kind of strange reduplication? Anyway, re for 'back' and pro for 'forth' is about it.
You scratch my back, and I'll scratch yours.
Are we talking about symbiosis again?
But where did the -ci- come from?
How about from "cis" meaning "on this side" - e.g. "cis Taurum", "cis Alpes"? Which is apparently related to a Sanskrit stem "ki".
On the subject of "ki" - here's more Nostraticist fodder: ki means "who" in Hungarian and French. Coincidence? Probably.