postoffice是名词吗

是名词，意思是邮局，例如：

1.I'm just going down to the post office.我正要到那边的邮局去。

2.We live just up the road, past the post office.我们就住在路的前面，刚过邮局的地方。

3.She went to the post office to draw her pension.她到邮局去领取她的养老金。