Grizzliest is an adjective that describes something as being rugged, wild, and fierce. There are a number of synonyms that can be used in place of grizzliest, including the following: untamed, ferocious, savage, violent, brutal, fierce, wild, rough, rugged, and dangerous. Each of these words conjures up images of something that is intimidating and dangerous. Whether you are talking about an animal, a landscape, or a person, these words all suggest something that should be approached with caution and respect. So if you are looking for a way to describe something that is tough, powerful, and formidable, use one of these synonyms in place of grizzliest.