the very fine thread made by spiders 蛛丝 - (literary)
any very light fine material 薄纱；精细织物 a gown of gossamer silk 女式丝绸长裙 the gossamer wings of a dragonfly 薄如轻纱的蜻蜓翅膀
Word OriginMiddle English: apparently from goose + summer, perhaps from the time of year around St Martin's summer, i.e. early November, when geese were eaten (gossamer being common then).