The Swedish word of this post is... Fan.
How is it pronounced? Faahn.
How is it used? It is a curse word, but it can be used as a name. "Fan, I hate this!" "Look at that Fan, what is he doing?"
The word has its roots in ancient Scandinavian, and every Scandinavian country used it (with little or no change). It is a word for the Devil, but today it maintains no connection with the devil or demons. Today, it is a simple curse word, and has about the same meaning and impact as the English curse word "Fuck".
Another variation exist of the word, which is Fy Fan (Füü Faahn), where Fy can be translated into "Shame (on you)!" or as a disgusted or disturbed reply, where Fy Fan works perfectly. "Fy fan, that's nasty."