The word 减肥 is formed by directly combining two meaningful characters: 减, which means "to reduce" or "to decrease", and 肥, which means "fat" or "obesity". Their conceptual meanings are merged in a straightforward, logical sequence, first the action (减) and then its target (肥), to create the single, compound concept of "to lose weight". It is a purpose-built term where the combined literal sense, "reduce fat", transparently conveys its intended meaning.