zompist bboard

What's the derivation of this word? As a South Slavic speaker, it sounds very strange, and since Russian already has "za" I don't see the point.

Well, there is a difference in meaning, I don't know if they're ever interchangeable in Russian - I've just found such a page:

http://www.alphadictionary.com/rusgrammar/for.html

According to Vasmer для is a shortened form of ORu. дѣлꙗ, from Common Slavic *dělja (similarly, modern Polish has dla, while in OPl. dziela is attested, too).

According to the ЭССЯ, Slavic adpositions such as дѣлꙗ/для, dziela/dla, dľa, dle, źěla, in South Slavic: dijel, delj have arisen due to a merger of the reflexes of Common Slavic words *dьlja (ultimately related to the adj. *dьlgъ or the nouns *dьlь, *dьlina) and *dělja (related to the noun *dělo), with a spatial and causal meaning, respectively. Also cf. such prepositions as Polish wedle (*vъ-dьlě).

I don't have my Boryś with me, so I can't tell you what he says.

BTW, in early records of some languages the forms tended to show up as postpositions (or inpositions?), just like ради.

I know that I`m resurrecting a semi-old thread here, but I thought this was interesting.

Belarusian apparently has two forms, дзеля and для. They seem to mean the same thing, though I`m no expert in Belarusian - I don`t know if there are subtle differences in the way the two forms are used. Are there any other Slavic languages besides Belarusian that have two separate forms?

Why aren't you asking on lingvoforum?

I visited that forum once a few years ago but I've forgotten about it. Maybe the people there might have some answers though, thanks for reminding me.