fjandi

Etymology
From, from. Cognate with Norwegian and Swedish, Danish , English , Dutch , German.

Noun

 * 1)  enemy
 * 2) devil, demon, fiend
 * 3) a term for another person (or thing) implying strong dislike or annoyment

Usage notes
The plural fjendur is used with the sense of “enemies”, but fjandar for “devils”. In the sense “enemy”, the word is rarely encountered in the singular anymore. In the sense “devil”, it is often used in the singular with the definite article to indicate the Devil (Satan).