Great gray is a word often used to describe something that is big, powerful, and maybe a little intimidating. However, if you're looking for synonyms to expand your vocabulary, there are plenty of other words that could fit the bill. For example, instead of great gray, you might say something is massive, colossal, or immense. If you want a word that conveys power and authority, formidable, commanding, or impressive could all be good options. And if you're looking for a more descriptive way to express the color gray, you could use words like ashen, slate, or pewter. With so many possibilities, you're sure to find a word that fits your needs.