The Chinese word "杀虫剂" (shāchóngjì) is a purpose-descriptive compound noun formed through logical semantic combination: the character "杀" (shā) means "to kill," "虫" (chóng) means "insect/pest," and "剂" (jì) denotes "chemical agent" or "substance." Together, they sequentially describe the function and category of the item—an agent whose specific purpose is to kill insects, thus directly and transparently creating the word for "insecticide" or "pesticide."