The word 亿万 is formed by combining two distinct Chinese numerical units, 亿 (yì, meaning "hundred million") and 万 (wàn, meaning "ten thousand"), not through a grammatical rule, but through a conceptual fusion where both large-scale quantifiers are joined to create a single, amplified idea of an immense, often incalculable number. This pairing does not represent a mathematical product, but rather a rhetorical and cultural device that harnesses the collective weight of these two vast measures to evoke a sense of limitless quantity, akin to "tens of millions upon millions" or "countless multitudes", emphasizing an overwhelming scale beyond ordinary calculation.