Captain America is a beloved superhero from the Marvel Comics Universe. He is a symbol of patriotism and justice, fighting for the greater good. When it comes to synonyms for Captain America, one could use "The Star-Spangled Avenger," as this nickname emphasizes his American heritage. Another option would be "The Sentinel of Liberty," highlighting his dedication to freedom and democracy. Some fans also refer to him as simply "Cap," which is shorter and more informal. Regardless of the synonym used, Captain America remains one of the most iconic superheroes in American pop culture.