Muscly is a word that is used to describe someone or something that is muscular or has well-developed muscles. However, there are many other words that can be used as synonyms for muscly. These include athletic, brawny, buff, chiseled, fit, hunky, ripped, robust, sinewy, strapping, strong, sturdy, and well-built. These words can be used to describe a wide range of things, such as a person's physique, an animal's strength, or even an inanimate object's durability. Using different synonyms can help to add variety to your writing and make it more interesting to read.