The word 强大 is formed by combining two characters whose core meanings reinforce and amplify each other conceptually. The first character, 强, conveys the idea of strength, force, or power. The second, 大, means big or great. They are placed side-by-side not merely to list attributes, but to create a fused concept where the quality of being "strong" is magnified to a scale of greatness, resulting in the holistic sense of "powerful", "formidable", or "immensely strong". The formation is intuitive, painting a picture of strength that is both potent and expansive.