The word 负担 is formed through a conceptual combination where the first character, 负, means to bear or carry (often a weight or duty), and the second character, 担, means to carry on a shoulder pole, a classic tool for transporting heavy loads. Together, they create a powerful metaphor: just as one physically shoulders a heavy pole with balanced weights, the compound word 负担 evokes the abstract idea of carrying a burden, responsibility, or obligation, merging the physical act of bearing weight with the psychological or social pressure of a duty.