down在羽絨服里是羽絨的意思。例如duck down，“鴨的絨毛”，即“鴨絨”。例句：A down coat is an insulated winter coat that is filled with fine feathers from a duck or goose. “羽絨服”是一種隔絕寒冷的（insulated）冬衣，里面填充了羽絨（fine feathers）。