What is the viking word for beast?

There isn't one single word in Old Norse, the language of the Vikings, that directly translates to "beast" in the same way we use it in modern English. However, depending on the specific meaning you're looking for, some words could be considered close approximations:

* "Dýr" - This translates to "animal" in general, but can also refer to a wild or dangerous animal, potentially akin to "beast."

* "Vildýr" - This literally means "wild animal," and could be used for a ferocious or untamed creature.

* "Mönstur" - This means "monster" and might be used to describe a mythical or particularly monstrous beast.

* "Úlfur" - This is simply "wolf," but considering the wolf's significance in Viking culture, it could be used in a metaphorical sense for a beastly or fierce person.

Ultimately, the best word would depend on the specific context and the type of beast you are referring to.