The Chinese word "大于" (dà yú), meaning "greater than," is a prepositional compound formed by combining the character "大" (dà), which means "big" or "great," with the classical Chinese preposition "于" (yú), which here denotes a comparative relationship ("in relation to" or "than"). This structure literally translates to "big in relation to," creating a fixed grammatical term used exclusively to indicate that one quantity or value exceeds another, most commonly seen in mathematical and comparative contexts.