measure word, numeral, noun · a measure word for a set of two corresponding items

我今天买了一双新鞋。

numeral, noun · two; twofold; dual; involving both sides

中国人结婚时，家里到处都贴着红双喜。

adjective, noun · even number; divisible by two

二、四、六是双，一、三、五是单。

numeral · surname Shuang

双先生在教育局工作。