wild beast; wild animal; brute
Refers to undomesticated, often dangerous animals; can also be used figuratively for a person acting in a brutal, uncivilized manner.
We heard the distant howl of a wild beast deep in the forest.
He became like a brute in his anger.
When he gets angry, his eyes take on a beast-like look.
A man camping in the mountains was attacked by a wild beast.
They make a living by hunting wild beasts in the forest.
獣 is a plain, general word for 'beast' or 'animal', while 野獣 specifically emphasizes that the beast lives untamed in the wild.
野獣 is a native Japanese term for a wild, brutish beast, while ビースト is a katakana loanword often used in fantasy or game contexts.
家畜 refers to domesticated livestock raised by humans, the direct opposite of a 野獣 living wild and untamed.
Compound of 野 (field, wild) and 獣 (beast, animal). The exact historical derivation is uncertain, but the combination naturally conveys the meaning of a wild animal.