fierce

Fierce describes someone or something that shows strong and intense energy, usually in a way that can be a little intimidating.

When people say something is fierce, they often mean it's really good at what it does - like a dog that's fierce at chasing squirrels. It could also describe someone who's fiercely loyal to their friends or family, meaning they stick up for them no matter what. The word "fierce" can even be used to describe how something looks, like a fierce storm with strong winds and heavy rain. In music, a band might have a fierce sound that gets you pumped up and moving.