What is a "number prophetess"?

Being isolated on their island, Icelandic people have fiercely defended their language both against evolution (the language hasn’t changed much in the last 800 years), and against the invasion of foreign words.

Whereas most languages let new English words slip through, the official policy is that linguists belonging to the Árni Magnússon Institute for Icelandic Studies invent new ones instead, usually by combination of existing vocables. 

So when the University of Iceland received its first computer, over 50 years ago, their was no Icelandic word to describe the new concept. So a new one was forged by the fusion of tala (number) and völva (prophetess).

The new word, tölva, thus means, rather poetically, “number prophetess”!

This Associated Press article gives further examples of such coined words